![Jeep Wrangler TJ](https://upload.wikimedia.org/wikipedia/commons/0/03/Jeep_Wrangler_TJ.jpg)
Four-wheel drive, also called 4×4 ("four by four") or 4WD, refers to a two-axled vehicle
drivetrain
A drivetrain (also frequently spelled as drive train or sometimes drive-train) is the group of components that deliver mechanical power from the prime mover to the driven components. In automotive engineering, the drivetrain is the components o ...
capable of providing
torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
to all of its wheels simultaneously. It may be full-time or on-demand, and is typically linked via a
transfer case
A transfer case is a part of the drivetrain of four-wheel-drive, all-wheel-drive, and other multiple powered axle vehicles. The transfer case transfers power from the transmission to the front and rear axles by means of drive shafts. It also syn ...
providing an additional output drive shaft and, in many instances, additional
gear range
A gear is a rotating circular machine part having cut teeth or, in the case of a cogwheel or gearwheel, inserted teeth (called ''cogs''), which mesh with another (compatible) toothed part to transmit (convert) torque and speed. The basic pr ...
s.
A four-wheel drive vehicle with torque supplied to both axles is described as
"all-wheel drive" (AWD). However, "four-wheel drive" typically refers to a set of specific components and functions, and intended off-road application, which generally complies with modern use of the terminology.
Definitions
Four-wheel-drive systems were developed in many different markets and used in many different
vehicle platform
A car platform is a shared set of common design, engineering, and production efforts, as well as major components, over a number of outwardly distinct models and even types of cars, often from different, but somewhat related, marques. It is pract ...
s. There is no universally accepted set of terminology that describes the various architectures and functions.
The terms used by various manufacturers often reflect marketing rather than engineering considerations or significant technical differences between systems.
SAE International
SAE International, formerly named the Society of Automotive Engineers, is a United States-based, globally active professional association and standards developing organization for engineering professionals in various industries. SAE Internatio ...
's standard J1952 recommends only the term "all-wheel drive" with additional subclassifications that cover all types of AWD/4WD/4x4 systems found on production vehicles.
[.]
4×4
"Four-by-four" or "4×4" is frequently used to refer to a class of vehicles in general. Syntactically, the first figure indicates the total number of axle ends and the second indicates the number of axle ends that are powered. Accordingly, 4×2 means a four-wheel vehicle that transmits engine torque to only two axle ends: the front two in
front-wheel drive
Front-wheel drive (FWD) is a form of engine and transmission layout used in motor vehicles, where the engine drives the front wheels only. Most modern front-wheel drive vehicles feature a transverse engine, rather than the conventional longit ...
or the rear two in
rear-wheel drive
Rear-wheel drive (RWD) is a form of engine and transmission layout used in motor vehicles, in which the engine drives the rear wheels only. Until the late 20th century, rear-wheel drive was the most common configuration for cars.
Most rear-wheel ...
. Similarly, a
6×4 vehicle has three axles, two of which provide torque to two axle ends each. If this vehicle were a truck with dual rear wheels on two rear axles, so actually having ten wheels, its configuration would still be formulated as 6x4. During World War II, the U.S. military would typically use spaces and a capital 'X' – as "4 X 2" or "6 X 4".
4WD
Four-wheel drive (4WD) refers to vehicles with two axles providing torque to four axle ends. In the North American market, the term generally refers to a system optimized for off-road driving conditions.
The term "4WD" is typically designated for vehicles equipped with a
transfer case
A transfer case is a part of the drivetrain of four-wheel-drive, all-wheel-drive, and other multiple powered axle vehicles. The transfer case transfers power from the transmission to the front and rear axles by means of drive shafts. It also syn ...
that switches between 2WD and 4WD operating modes, either manually or automatically.
AWD
All-wheel drive (AWD) was historically synonymous with "four-wheel drive" on four-wheeled vehicles, and
six-wheel drive
Six-wheel drive (6WD or 6×6) is an all-wheel drive drivetrain configuration of three axles with at least two wheels on each axle capable of being driven simultaneously by the vehicle's engine. Unlike four-wheel drive drivetrains, the configurat ...
on
6×6
Six-wheel drive (6WD or 6×6) is an all-wheel drive drivetrain configuration of three axles with at least two wheels on each axle capable of being driven simultaneously by the vehicle's engine. Unlike four-wheel drive drivetrains, the configurat ...
s, and so on, being used in that fashion at least as early as the 1920s. Today in North America, the term is applied to both heavy vehicles and light passenger vehicles. When referring to heavy vehicles, the term is increasingly applied to mean "permanent multiple-wheel drive" on
2×2, 4×4, 6×6, or
8×8
Eight-wheel drive, often notated as 8WD or 8×8, is a drivetrain configuration that allows all eight wheels of an eight-wheeled vehicle to be drive wheels (that is, to receive power from the engine) simultaneously. Unlike four-wheel drive drivetr ...
drive-train systems that include a
differential between the front and rear drive shafts.
This is often coupled with some sort of antislip technology, increasingly hydraulic-based, that allows differentials to spin at different speeds, but still be capable of transferring the torque from a wheel with poor traction to one with better. Typical AWD systems work well on all surfaces, but are not intended for more extreme off-road use.
When used to describe AWD systems in light passenger vehicles, it refers to a system that applies torque to all four wheels (permanently or on-demand) or is targeted at improving on-road traction and performance (particularly in inclement conditions), rather than for off-road applications.
Some all-wheel drive electric vehicles use one motor for each axle, thereby eliminating a mechanical differential between the front and rear axles. An example of this is the
dual-motor variant of the
Tesla Model S
The Tesla Model S is a Battery electric vehicle, battery-powered liftback car serving as the flagship model of Tesla, Inc. The Model S features a dual-motor, all-wheel drive layout, although earlier versions of the Model S featured a rear-moto ...
, which controls the torque distribution between its two motors electronically.
SAE recommended practices
According to the SAE International standard J1952, AWD is the preferred term for all the systems described above. The standard subdivides AWD systems into three categories.
Part-time AWD systems require driver intervention to couple and decouple the secondary axle from the primarily driven axle, and these systems do not have a center differential (or similar device). The definition notes that part-time systems may have a low range.
Full-time AWD systems drive both front and rear axles at all times via a center (interaxle) differential. The torque split of that differential may be fixed or variable depending on the type of center differential. This system can be used on any surface at any speed. The definition does not address the inclusion or exclusion of a low-range gear.
On-demand AWD systems drive the secondary axle via an active or passive coupling device or "by an independently powered drive system". The standard notes that in some cases, the secondary drive system may also provide the primary vehicle propulsion. An example is a hybrid AWD vehicle where the primary axle is driven by an internal combustion engine and the secondary axle is driven by an electric motor. When the internal combustion engine is shut off, the secondary, electrically driven axle is the only driven axle. On-demand systems function primarily with only one powered axle until torque is required by the second axle. At that point, either a passive or active coupling sends torque to the secondary axle.
In addition to the above primary classifications, the J1952 standard notes secondary classifications resulting in a total of eight systems, designated as:
*Part-time nonsynchro
*Part-time synchro
*Full-time fixed torque
*Full-time variable-torque passive
*Full-time variable-torque active
*On-demand synchro variable-torque passive
*On-demand synchro variable-torque active
*On-demand independently powered variable-torque active
Design
Differentials
Two wheels fixed to the same axle (but on the opposite axle ends) need to turn at different speeds as a vehicle goes around a curve. The reason is that the wheel that is located on the inner side of the curve needs to travel less distance than the opposite wheel for the same duration of time. However, if both wheels are connected to the same axle driveshaft, they always have to spin at the same speed relative to each other. When going around a curve, this either forces one of the wheels to slip, if possible, to balance the apparent distance covered, or creates uncomfortable and mechanically stressful wheel hop. To prevent this, the wheels are allowed to turn at different speeds using a mechanical or hydraulic
differential. This allows one
driveshaft
A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power and torque and rotation, usually used to connect ...
to independently drive two output shafts, axles that go from the differential to the wheel, at different speeds.
The differential does this by distributing angular force (in the form of
torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
) evenly, while distributing
angular velocity
In physics, angular velocity or rotational velocity ( or ), also known as angular frequency vector,(UP1) is a pseudovector representation of how fast the angular position or orientation of an object changes with time (i.e. how quickly an objec ...
(turning speed) such that the average for the two output shafts is equal to that of the differential
ring gear
An epicyclic gear train (also known as a planetary gearset) consists of two gears mounted so that the center of one gear revolves around the center of the other. A carrier connects the centers of the two gears and rotates the planet and sun gea ...
. When powered, each axle requires a differential to distribute power between the left and right sides. When power is distributed to all four wheels, a third or 'center' differential can be used to distribute power between the front and rear axles.
The described system handles extremely well, as it is able to accommodate various forces of movement and distribute power evenly and smoothly, making slippage unlikely. Once it does slip, however, recovery is difficult. If the left front wheel of a 4WD vehicle slips on an icy patch of road, for instance, the slipping wheel spins faster than the other wheels due to the lower traction at that wheel. Since a differential applies equal torque to each half-shaft, power is reduced at the other wheels, even if they have good traction. This problem can happen in both 2WD and 4WD vehicles, whenever a driven wheel is placed on a surface with little traction or raised off the ground. The simplistic design works acceptably well for 2WD vehicles. It is much less acceptable for 4WD vehicles, because 4WD vehicles have twice as many wheels with which to lose traction, increasing the likelihood that it may happen. 4WD vehicles may also be more likely to drive on surfaces with reduced traction. However, since torque is divided between four wheels rather than two, each wheel receives roughly half the torque of a 2WD vehicle, reducing the potential for wheel slip.
Limiting slippage
Many differentials have no way of limiting the amount of engine power that gets sent to their attached output shafts. As a result, if a tire loses traction on acceleration, either because of a low-traction situation (e.g., driving on gravel or ice) or the engine power overcomes available traction, the tire that is not slipping receives little or no power from the engine. In very low-traction situations, this can prevent the vehicle from moving at all. To overcome this, several designs of differentials can either limit the amount of slip (these are called 'limited-slip' differentials) or temporarily lock the two output shafts together to ensure that engine power reaches all driven wheels equally.
Locking differential
A locking differential is a mechanical component, commonly used in vehicles, designed to overcome the chief limitation of a standard open differential by essentially "locking" both wheels on an axle together as if on a common shaft. This forces ...
s work by temporarily locking together a differential's output shafts, causing all wheels to turn at the same rate, providing torque in case of slippage. This is generally used for the center differential, which distributes power between the front and the rear axles. While a drivetrain that turns all wheels equally would normally fight the driver and cause handling problems, this is not a concern when wheels are slipping.
The two most common factory-installed locking differentials use either a computer-controlled
multiplate clutch
Multiplate multiple electrode aggregometry (MEA) is a test of platelet function in whole blood. The test can be used to diagnose platelet disorders, monitor antiplatelet therapy, and is also investigated as a potential predictor of transfusion requ ...
or
viscous coupling unit
A viscous coupling is a mechanical device which transfers torque and rotation by the medium of a viscous fluid.
Design
Rotary viscous couplings with interleaved, perforated plates and filled with viscous fluids are used in automotive system ...
to join the shafts, while other differentials are more commonly used on off-road vehicles generally use manually operated locking devices. In the multi-plate clutch, the vehicle's computer senses slippage and locks the shafts, causing a small jolt when it activates, which can disturb the driver or cause additional traction loss. In the viscous coupling differentials, the
shear stress
Shear stress, often denoted by (Greek: tau), is the component of stress coplanar with a material cross section. It arises from the shear force, the component of force vector parallel to the material cross section. ''Normal stress'', on the ot ...
of high shaft speed differences causes a
dilatant
A dilatant (, ) (also termed shear thickening) material is one in which viscosity increases with the rate of shear strain. Such a ''shear thickening fluid'', also known by the initialism ''STF'', is an example of a non-Newtonian fluid. This beha ...
fluid in the differential to become solid, linking the two shafts. This design suffers from fluid degradation with age and from
exponential
Exponential may refer to any of several mathematical topics related to exponentiation, including:
*Exponential function, also:
**Matrix exponential, the matrix analogue to the above
* Exponential decay, decrease at a rate proportional to value
*Exp ...
locking behavior. Some designs use gearing to create a small rotational difference that hastens torque transfer.
A third approach to limiting slippage is taken by a
Torsen
Torsen Torque-Sensing (full name Torsen traction) is a type of limited-slip differential used in automobiles.
It was invented by American Vernon Gleasman and manufactured by the Gleason Corporation. Torsen is a portmanteau of Torque-Sensing. ''TO ...
differential, which allows the output shafts to receive different amounts of torque. This design does not provide for traction when one wheel is spinning freely, where no torque exists, but provides excellent handling in less extreme situations. A typical Torsen II differential can deliver up to twice as much torque to the high-traction side before traction is exceeded at the low-traction side.
A fairly recent innovation in automobiles is electronic
traction control
A traction control system (TCS), also known as ASR (from german: Antriebsschlupfregelung, lit=drive slippage regulation), is typically (but not necessarily) a secondary function of the electronic stability control (ESC) on production motor vehicle ...
. It typically uses a vehicle's braking system to slow a spinning wheel. This forced slowing emulates the function of a limited-slip differential, and by using the brakes more aggressively to ensure wheels are being driven at the same speed, can also emulate a locking differential. This technique normally requires wheel sensors to detect when a wheel is slipping, and only activates when wheel slip is detected. Therefore, typically no mechanism exists to actively prevent wheel slip (i.e., locking the differential in advance of wheel slip is not possible); rather, the system is designed to expressly permit wheel slip to occur, and then to attempt to send torque to the wheels with the best traction. If preventing all-wheel slip is a requirement, this is a limiting design.
Operating modes
The architecture of an AWD/4WD system can be described by showing its possible operating modes.
A single vehicle may have the ability to operate in multiple modes depending on driver selection. The different modes are:
*Two-wheel drive mode – In this mode, only one axle (typically the rear axle) is driven. The drive to the other axle is disconnected. The operating torque split ratio is 0:100.
*Four-wheel drive mode – Here, depending on the nature of torque transfer to the axles, three submodes (below) can be defined.
*Part-time mode – The front and rear axle drives are rigidly coupled in the transfer case. Since the driveline does not permit any speed differentiation between the axles and would cause driveline wind-up, this mode is recommended only for part-time use in off-road or loose-surface conditions where driveline wind-up is unlikely. Up to full torque could go to either axle, depending on the road conditions and the weight over the axles.
*Full-time mode – Both axles are driven at all times, but an interaxle differential permits the axles to turn at different speeds as needed. This allows the vehicle to be driven full-time in this mode, regardless of the road surface, without fear of driveline wind-up. With standard bevel-gear differentials, the torque split is 50:50. Planetary differentials can provide asymmetric torque splits as needed. A system that operates permanently in the full-time mode is sometimes called all-the-time 4WD, all-wheel drive, or AWD. If the interaxle differential is locked out, then the mode reverts to a part-time mode.
*On-demand mode – In this mode, the transfer case operates primarily in the 2WD mode. Torque is transferred to the secondary axle as needed by modulating the transfer clutch from open to a rigidly coupled state, while avoiding any driveline wind-up. The torque modulation may be achieved by active electronic/hydraulic control systems, or by passive devices, based on wheel slip or wheel torque, as described in the section on traction control systems.
In addition to these basic modes, some implementations can combine these modes. The system could have a clutch across the center differential, for example, capable of modulating the front axle torque from a full-time mode with the 30:70 torque split of the center differential to the 0:100 torque split of the 2WD mode.
History
Late 1800s
In 1893, before the establishment of the modern automotive industry in Britain, English engineer
Bramah Joseph Diplock
Bramah Joseph Diplock (27 April 1857 – 9 August 1918) was an English inventor who invented the pedrail wheel in 1899 and the pedrail chaintrack, a type of caterpillar track, in 1907.
Diplock was born in Chelsea, London to Thomas Bramah Diplo ...
patented a four-wheel drive system for a steam-powered
traction engine
A traction engine is a steam engine, steam-powered tractor used to move heavy loads on roads, plough ground or to provide power at a chosen location. The name derives from the Latin ''tractus'', meaning 'drawn', since the prime function of any t ...
, including four-wheel steering and three
differentials, which was subsequently built. The development also incorporated Bramah's
Pedrail wheel
The pedrail wheel is a type of all-terrain wheel developed in the late 19th and early 20th century by Londoner Bramah Joseph Diplock. It consists of a series of "feet" (''pedes'' in Latin) connected to pivots on a wheel. As the wheel travels, ...
system in what was one of the first four-wheel drive automobiles to display an intentional ability to travel on challenging road surfaces. It stemmed from Bramagh's previous idea of developing an engine that would reduce the amount of damage to public roads.
Ferdinand Porsche
Ferdinand Porsche (3 September 1875 – 30 January 1951) was an Austrian-German automotive engineer and founder of the Porsche AG. He is best known for creating the first gasoline–electric hybrid vehicle (Lohner–Porsche), the Volkswag ...
designed and built a four-wheel-driven
electric vehicle
An electric vehicle (EV) is a vehicle that uses one or more electric motors for propulsion. It can be powered by a collector system, with electricity from extravehicular sources, or it can be powered autonomously by a battery (sometimes cha ...
for the ''k. u. k. Hofwagenfabrik Ludwig Lohner & Co.'' in Vienna in 1899, presented to the public during the 1900 World Exhibition in Paris. The vehicle was a
series hybrid
Hybrid vehicle drivetrains transmit power to the driving wheels for hybrid vehicles. A hybrid vehicle has multiple forms of motive power.
Hybrids come in many configurations. For example, a hybrid may receive its energy by burning gasoline, but sw ...
car that used an electric
hub motor
The wheel hub motor (also called wheel motor, wheel hub drive, hub motor or in-wheel motor) is an electric motor that is incorporated into the hub of a wheel and drives it directly.
History
* First wheel motor concept: Wellington Adams of ...
at each wheel, powered by batteries, which were in turn charged by a gasoline-engine generator.
[ ''See year 1898''.] It was clumsily heavy, and due to its unusual status, the so-called ''
Lohner–Porsche
The Lohner–Porsche Mixed Hybrid (sometimes incorrectly referred to as ''Löhner–Porsche'') was the first gasoline-electric hybrid vehicle.
It was developed by Ferdinand Porsche at Lohner-Werke. The first prototypes were two-wheel drive, b ...
'' is not frequently given its credit as the first four-wheel driven automobile.
1900s–1920s
![Jeffery Quad truck with U](https://upload.wikimedia.org/wikipedia/commons/c/c2/Jeffery_Quad_truck_with_U.S._Marines.jpg)
The world's first four-wheel-drive car directly powered by an internal-combustion engine, and the first with a
front-engine, four-wheel-drive layout
In automotive design, an F4, or front-engine, four-wheel drive (4WD) layout places the internal combustion engine at the front of the vehicle and drives all four roadwheels. This layout is typically chosen for better control on many surfaces, a ...
, was the Dutch ''
Spyker
Spyker or Spijker was a Dutch carriage, automobile and aircraft manufacturer, started in 1880 by blacksmiths Jacobus and Hendrik-Jan Spijker. Originally located in Hilversum, the company relocated to Trompenburg, Amsterdam in 1898.
Notable produ ...
'' 60 H.P., Commissioned for the Paris to Madrid race of 1903, it was presented that year by brothers Jacobus and Hendrik-Jan Spijker of
Amsterdam
Amsterdam ( , , , lit. ''The Dam on the River Amstel'') is the Capital of the Netherlands, capital and Municipalities of the Netherlands, most populous city of the Netherlands, with The Hague being the seat of government. It has a population ...
.
The two-seat sports car featured permanent four-wheel drive and was also the first car equipped with a six-cylinder engine, as well as four-wheel braking. Later used as a hill-climb racer, it is now an exhibit in the
Louwman Museum
The Louwman Museum is a museum for historic cars, coaches, and motorcycles in The Hague, Netherlands. It is situated on the Leidsestraatweg near the A44 highway. The museum's former names are "Nationaal Automobiel Museum" and "Louwman Collectio ...
(the former Nationaal Automobiel Museum) in
the Hague
The Hague ( ; nl, Den Haag or ) is a city and municipality of the Netherlands, situated on the west coast facing the North Sea. The Hague is the country's administrative centre and its seat of government, and while the official capital of ...
, the Netherlands.
Designs for four-wheel drive in America first came from the
Twyford Motor Car Company Introduction
Robert E. Twyford had an important role in the development of the automobile. He originally started out as a building contractor in Pittsburgh, Pennsylvania, but later turned to developing automobiles. In 1900, the patent office gr ...
.
The
Reynolds-Alberta Museum
The Reynolds-Alberta Museum is an agricultural, industrial, and transportation museum in Wetaskiwin, Alberta, Canada. The museum is situated on an property containing the main museum building, an aviation display hangar, and its storage facility. ...
has a four-wheel-drive vehicle, named "
Michigan
Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and the ...
", from 1905 in unrestored storage.
The first four-wheel-drive vehicles to go into mass production were built by (what became) the American
Four Wheel Drive
Four-wheel drive, also called 4×4 ("four by four") or 4WD, refers to a two-axled vehicle drivetrain capable of providing torque to all of its wheels simultaneously. It may be full-time or on-demand, and is typically linked via a transfer case ...
Auto Company (FWD) of
Wisconsin
Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...
, founded in 1908. (not to be confused with the term "FWD" as an acronym for ''front-wheel-drive'')
Along with the 1- and 2-ton
Nash Quad
The Jeffery Quad, also known as the Nash Quad or Quad is a four-wheel drive, 1-ton rated truck that was developed and built by the Thomas B. Jeffery Company from 1913 in Kenosha, Wisconsin, and after 1916 by Nash Motors, which acquired the Jeffer ...
(see below), the 3-ton FWD Model B became a standard military four-wheel-drive truck for the U.S. Army in World War I. Some 16,000 FWD Model B trucks were built for the
British
British may refer to:
Peoples, culture, and language
* British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies.
** Britishness, the British identity and common culture
* British English, ...
and American armies during World War I – about half by FWD and the rest by other licensed manufacturers. Only about 20% of the trucks built were four-wheel drives, but the 4x4s were more often on the front lines.
About 11,500 of the
Jeffery /
Nash Quad
The Jeffery Quad, also known as the Nash Quad or Quad is a four-wheel drive, 1-ton rated truck that was developed and built by the Thomas B. Jeffery Company from 1913 in Kenosha, Wisconsin, and after 1916 by Nash Motors, which acquired the Jeffer ...
trucks were built for similar use between 1913 and 1919. The Quad not only came with four-wheel-drive and four-wheel brakes, but also featured four-wheel steering.
The Quad was one of the first successful four-wheel drive vehicles ever to be made, and its production continued for 15 years with a total of 41,674 units made by 1928.
Daimler-Benz
The Mercedes-Benz Group Aktiengesellschaft, AG (previously named Daimler-Benz, DaimlerChrysler and Daimler) is a German Multinational corporation, multinational automotive corporation headquartered in Stuttgart, Baden-Württemberg, Germany. It ...
also has a history in four-wheel drive. After the
Daimler Motoren Gesellschaft
Daimler-Motoren-Gesellschaft (abbreviated as DMG, also known as ''Daimler Motors Corporation'') was a German engineering company and later automobile manufacturer, in operation from 1890 until 1926. Founded by Gottlieb Daimler (1834–1900) and ...
had built a four-wheel-driven vehicle called ''Dernburg-Wagen'', also equipped with
four-wheel steering
Steering is a system of components, linkages, and other parts that allows a driver to control the direction of the vehicle.
Introduction
The most conventional steering arrangement allows a driver to turn the front wheels of a vehicle using ...
, in 1907, that was used by German colonial civil servant, Bernhard Dernburg, in
Namibia
Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...
; Mercedes and BMW, in 1926, introduced some rather sophisticated four-wheel drives, the G1, the G4, and G4 following. Mercedes and BMW developed this further in 1937.
1930s
![GAZ-64-bw](https://upload.wikimedia.org/wikipedia/commons/9/9b/GAZ-64-bw.jpg)
The American
Marmon-Herrington Company
The Marmon-Herrington Company, Inc. is an American manufacturer of axles and transfer cases for trucks and other vehicles. Earlier, the company built military vehicles and some tanks during World War II, and until the late 1950s or early 1960s was ...
was founded in 1931 to serve a growing market for moderately priced four-wheel-drive vehicles. Marmon-Herrington specialized in converting
Ford
Ford commonly refers to:
* Ford Motor Company, an automobile manufacturer founded by Henry Ford
* Ford (crossing), a shallow crossing on a river
Ford may also refer to:
Ford Motor Company
* Henry Ford, founder of the Ford Motor Company
* Ford F ...
trucks to four-wheel drive and got off to a successful start by procuring contracts for military and commercial aircraft refueling trucks, 4×4 chassis for towing light weaponry, and an order from the Iraqi Pipeline Company for what were the largest trucks built at the time.
The early Marmon-Herringtons proved to be the exception to the rule — 4WD cars and trucks developed in the 1930s were mainly built for governments, with (future) warfare applications in mind.
Dodge developed its first four-wheel-drive truck in 1934 — a military ton designated K-39-X-4(USA), of which 796 units were built for the U.S. Army in several configurations.
[1943 Dodge WC-51 Weapons Carrier, Power & Glory – FourWheeler.com]
/ref> Timken supplied front axles and transfer cases, added to militarized a civilian truck. The Timken transfer case
A transfer case is a part of the drivetrain of four-wheel-drive, all-wheel-drive, and other multiple powered axle vehicles. The transfer case transfers power from the transmission to the front and rear axles by means of drive shafts. It also syn ...
was the first ''part-time'' design, that allowed the driver to engage or disengage four-wheel drive using a lever inside the cab.[1946–1948 Dodge Power Wagon – HowStuffWorks]
/ref> In spite of the limited 1930s U.S. military budgets, the '34 truck was liked well-enough that a more modern ton truck was developed, and 1,700 RF-40-X-4(USA) trucks were produced in 1938, and 292 TF-40-X-4(USA) in 1939.[
Starting in 1936, Japanese company ]Tokyu Kurogane Kogyo
, or Kurogane, was one of the first Japanese automakers. It built vehicles from about 1926 until 1962 when a subsidiary of Nissan, called Nissan Machinery (Nissan Koki Co., Ltd. 日産工機), assumed operations as the company had become a member ...
built roughly 4,700 four-wheel-drive roadsters, called the Kurogane Type 95
The Type 95 was a Japanese scout car built by , and was used during the war with China and World War II in the East. Between 1936 and 1944 approximately 4,700 were built. It was the only completely Japanese designed reconnaissance car ever use ...
reconnaissance car, used by the Imperial Japanese Army from 1937 until 1944, during the Second Sino-Japanese War
The Second Sino-Japanese War (1937–1945) or War of Resistance (Chinese term) was a military conflict that was primarily waged between the Republic of China and the Empire of Japan. The war made up the Chinese theater of the wider Pacific Th ...
. Three different bodystyles were manufactured – a two-door roadster, a two-door pickup truck, and a four-door phaeton, all equipped with a transfer case that engaged the front wheels, powered by a 1.3-litre, two-cylinder, air-cooled OHV V-twin engine.
The 1937 Mercedes-Benz G5 and BMW 325 4×4 featured full-time four-wheel drive, four-wheel steering, three locking differentials, and fully independent suspension. They were produced because of a government demand for a four-wheel-drive passenger vehicle. The modern G-series/Wolf such as the G500 and G55 AMG still feature some of the attributes, with the exception of fully independent suspension, since it can compromise ground clearance. The Unimog
The Unimog (, ) is a range of multi-purpose tractors, trucks and lorries that has been produced by Boehringer from 1948 until 1951, and by Daimler Truck (formerly Daimler-Benz, DaimlerChrysler and Daimler AG) since 1951. In the United States and ...
is also a result of Mercedes 4x4 technology.
The first Russian-produced four-wheel-drive vehicle, also in part for civilian use, was the GAZ-61
The GAZ-61 is a four wheel drive car from USSR manufacturer GAZ first introduced in 1938 by designer V. A. Gratchev, to replace his too-complex model GAZ-M2.
History
It was made by putting a GAZ-M1 body on a four-wheel-drive chassis (one of th ...
, developed in the Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...
in 1938. "Civilian use" may be a bit of a misnomer, as most, if not all, were used by the Soviet government and military (as command cars), but the GAZ-61-73 version is the first four-wheel-drive vehicle with a normal closed sedan body. Elements of the chassis were used in subsequent military vehicles such as the 1940 GAZ-64
The GAZ-64 was a 4x4 vehicle made by GAZ (Gorkovsky Avtomobilny Zavod, translated as Gorky Automobile Plant, which originally was a cooperation between Ford and the Soviet Union), succeeding the earlier GAZ-61. Its design was led by Vitaliy Grac ...
and the 1943 GAZ-67
The GAZ-67 and the GAZ-67B (from January 1944) were general-purpose four-wheel drive Soviet military vehicles built by GAZ starting in 1943. By the end of the war, it was the Soviet equivalent of the World War II jeep.
The GAZ-67 was a further d ...
, as well as the postwar GAZ-69
The GAZ-69 is a four-wheel drive off-road vehicle produced by GAZ (ГАЗ, or ''Gorkovsky Avtomobilnyi Zavod'', Gorky Automobile Factory) between 1953 and 1956 and then by UAZ, in 1956–1972, though all of these light truck class vehicles were k ...
, and the properly civilian GAZ-M-72, based on the rear-wheel drive
Rear-wheel drive (RWD) is a form of engine and transmission layout used in motor vehicles, in which the engine drives the rear wheels only. Until the late 20th century, rear-wheel drive was the most common configuration for cars.
Most rear-wheel ...
GAZ-20 "Victory" and built from 1955 to 1958. Soviet civilian life did not allow the proliferation of civilian products such as the Jeep
Jeep is an American automobile marque, now owned by multi-national corporation Stellantis. Jeep has been part of Chrysler since 1987, when Chrysler acquired the Jeep brand, along with remaining assets, from its previous owner American Moto ...
in North America, but through the 1960s, the technology of Soviet 4×4 vehicles stayed on par with British, German, and American models, even exceeding it in some aspects, and for military purposes just as actively developed, produced, and used.
World War II – a leap in AWD proliferation
Until "go-anywhere" vehicles were needed for the military on a large scale, four-wheel drive and all-wheel-drive
An all-wheel drive vehicle (AWD vehicle) is one with a powertrain capable of providing power to all its wheels, whether full-time or on-demand.
The most common forms of all-wheel drive are:
;1x1 : All unicycles Reflecting one axle with one w ...
vehicles had not found their place. The World War II Jeep, originally developed by American Bantam
The American Bantam Car Company was an American automobile manufacturing company incorporated in the state of Pennsylvania. American Bantam is credited with the invention of the Original Jeep in 1940. The company's founders, Roy Evans and Willia ...
, but mass-produced by Willys
Willys (pronounced , "Willis" )
was a brand name used by Willys–Overland Motors, an American automobile company, founded by John North Willys. It was best known for its design and production of World War II era and later military jeeps (MBs ...
and Ford, became the best-known four-wheel-drive vehicle in the world during the war. The American Dodge WC series
The Dodge WC series, sometimes nicknamed 'Beeps', were a prolific range of light 4WD and medium 6WD military utility trucks, produced by Dodge / Fargo during World . Together with the -ton jeeps produced by Willys and Ford, the Dodge to ...
and Chevrolet G506
The G-506 trucks, -ton, 4x4, produced as the Chevrolet G7100 (and originally G4100) models, were a series of (light) medium four wheel drive trucks used by the United States Army and its allies during and after World War II. This series came in s ...
4x4 variants were also produced by the hundreds of thousands, as well as the Canadian Military Pattern truck
Canadian Military Pattern (CMP) trucks were mutually coherent ranges of military trucks, made in large numbers, in several classes and numerous versions, by Canada's branches of the U.S. 'Big Three' auto-makers during World War II, compliant to ...
s, of which 4x4s were by far the most prevalent of their various driveline configurations. All told, North America built about million 4x4 driven vehicles during the war,
Availability of certain critical components, such transfer cases and especially constant-velocity joint
Constant-velocity joints (also known as homokinetic or CV joints) are mechanical joints which allow a drive shaft to transmit power through a variable angle, at constant rotational speed, without an appreciable increase in friction or Backlash (e ...
s affected development. Though not used much on commercial vehicles,Front-wheel drive
Front-wheel drive (FWD) is a form of engine and transmission layout used in motor vehicles, where the engine drives the front wheels only. Most modern front-wheel drive vehicles feature a transverse engine, rather than the conventional longit ...
vehicles had not yet become common at that time all-wheel drive vehicles all needed these; and they would use two or three times the number of driven axles, meaning more gears to cut for all the differentials. Produced up to the war by a few specialized firms with limited capacity, from spring 1942, Ford, Dodge, and Chevrolet joined in fabricating these in a quantity more than a 100-fold greater than in 1939.
Although Russia had their own jeep-like vehicle (the GAZ-64) up and running in 1940, a year earlier than the American jeep, in the early years of the war, they relied significantly on Lend-Lease
Lend-Lease, formally the Lend-Lease Act and introduced as An Act to Promote the Defense of the United States (), was a policy under which the United States supplied the United Kingdom, the Soviet Union and other Allied nations with food, oil, ...
vehicles, provided by the western allies. In 1943, they launched a further-developed version: the GAZ-67
The GAZ-67 and the GAZ-67B (from January 1944) were general-purpose four-wheel drive Soviet military vehicles built by GAZ starting in 1943. By the end of the war, it was the Soviet equivalent of the World War II jeep.
The GAZ-67 was a further d ...
.
By contrast, the Axis powers
The Axis powers, ; it, Potenze dell'Asse ; ja, 枢軸国 ''Sūjikukoku'', group=nb originally called the Rome–Berlin Axis, was a military coalition that initiated World War II and fought against the Allies. Its principal members were ...
' closest equivalent to the jeep, the VW Kübelwagen
Volkswagen (),English: , . abbreviated as VW (), is a German Automotive industry, motor vehicle manufacturer headquartered in Wolfsburg, Lower Saxony, Germany. Founded in 1937 by the German Labour Front under the Nazi Party and revived into a ...
, of which only some 50,000 were built, though being equipped with portal gear
Portal axles (or portal gear lifts) are an off-road vehicle suspension and drive technology where the axle tube or the half-shaft is off-set from – usually above – the center of the wheel hub and where driving power is transferred to each whe ...
hubs, only had rear-wheel drive.
1945–1960s
Willys introduced the model CJ-2A in 1945, the first full-production four-wheel-drive vehicle for sale in the general marketplace. Due to the ubiquitous World War II Jeep's success, its rugged utilitarianism set the pattern for many four-wheel-drive vehicles to come. Hot on its heels, Dodge also started production of the civilian 4WD Power Wagon trucks, for the 1946 model year. Both the Willys and the Dodge were developed directly from their WW II predecessors.
Equally boxy to the Jeep, and also inline-four powered, the Land Rover
Land Rover is a British brand of predominantly four-wheel drive, off-road capable vehicles, owned by multinational car manufacturer Jaguar Land Rover (JLR), since 2008 a subsidiary of India's Tata Motors. JLR currently builds Land Rovers ...
appeared at the Amsterdam Motor Show in 1948. Originally conceived as a stop-gap product for the struggling Rover car company, despite chronic underinvestment, it succeeded far better than their passenger cars. Inspired by a Willys MB
The Willys MB and the Ford GPW, both formally called the U.S. Army Truck, -ton, 4×4, Command Reconnaissance, commonly known as the Willys Jeep, Jeep, or jeep, and sometimes referred to by its List of U.S. military vehicles by supply catalog ...
– the ubiquitous WWII "jeep" – that was frequently run off-road on the farm belonging to chief engineer Maurice Wilks
Maurice Fernand Cary Wilks (19 August 19048 September 1963) was a British automotive and aeronautical engineer, and by the time of his death in 1963, was the chairman of the Rover Company, a British car manufacturer. He was the founder of the ...
, Land Rover developed the more refined yet still off-road capable luxury 4WD Range Rover
Range may refer to:
Geography
* Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra)
** Mountain range, a group of mountains bordered by lowlands
* Range, a term used to i ...
in the 1970s.
With the acquisition of the "Jeep" name in 1950, Willys had cornered the brand. Its successor, Kaiser Jeep
Kaiser Jeep was the result of the 1953 merger of Kaiser Motors, an independent passenger car maker based in Willow Run, Michigan, with the Toledo, Ohio-based Willys-Overland Company.
Willys-Overland had been at one point before World War II th ...
, introduced a revolutionary 4WD wagon called the Wagoneer
The Jeep Wagoneer is a sport utility vehicle (SUV) nameplate of Jeep vehicles, with several models marketed for the 1963 through 1993 model years and again since the 2022 model year.
Various versions of the Wagoneer were manufactured in the US ...
in 1963. Not only was it technically innovative, with independent front suspension
Independent suspension is any automobile suspension system that allows each wheel on the same axle to move vertically (i.e. reacting to a bump on the road) independently of the others. This is contrasted with a beam axle or deDion axle system in w ...
and the first automatic transmission
An automatic transmission (sometimes abbreviated to auto or AT) is a multi-speed transmission used in internal combustion engine-based motor vehicles that does not require any input from the driver to change forward gears under normal driving c ...
coupled to 4WD, but also it was equipped and finished as a regular passenger automobile. In effect, it was the ancestor of the modern SUV
A sport utility vehicle (SUV) is a car classification that combines elements of road-going passenger cars with features from off-road vehicles, such as raised ground clearance and four-wheel drive.
There is no commonly agreed-upon definitio ...
. The luxury AMC
AMC may refer to:
Film and television
* AMC Theatres, an American movie theater chain
* AMC Networks, an American entertainment company
** AMC (TV channel)
** AMC+, streaming service
** AMC Networks International, an entertainment company
*** AM ...
or Buick
Buick () is a division of the American automobile manufacturer General Motors (GM). Started by automotive pioneer David Dunbar Buick in 1899, it was among the first American marques of automobiles, and was the company that established General ...
V8-powered Super Wagoneer produced from 1966 to 1969 raised the bar even higher.
Jensen applied the Formula Ferguson (FF) full-time all-wheel-drive system to 318 units of their Jensen FF
The Jensen FF is a four-wheel drive grand tourer produced by British car manufacturer Jensen Motors between 1966 and 1971. It was the first non all-terrain production car equipped with four-wheel drive and an anti-lock braking system. The powe ...
built from 1966 to 1971, marking the first time 4WD was used in a production GT sports car. While most 4WD systems split torque evenly, the Jensen split torque roughly 40% front, 60% rear by gearing the front and rear at different ratios.
1970s–1990s
American Motors Corporation
American Motors Corporation (AMC; commonly referred to as American Motors) was an American automobile manufacturing company formed by the merger of Nash-Kelvinator Corporation and Hudson Motor Car Company on May 1, 1954. At the time, it was the ...
(AMC) acquired Kaiser's Jeep Division in 1970 and quickly upgraded and expanded the entire line of off-road 4WD vehicles. With its added roadworthiness, the top-range full-sized Grand Wagoneer continued to compete with traditional luxury cars
A luxury car is a car that provides increased levels of comfort, equipment, amenities, quality, performance, and associated status compared to moderately priced cars.
The term is subjective and reflects both the qualities of the car and the b ...
. Partially hand-built, it was relatively unchanged during its production through 1991, even after Chrysler
Stellantis North America (officially FCA US and formerly Chrysler ()) is one of the " Big Three" automobile manufacturers in the United States, headquartered in Auburn Hills, Michigan. It is the American subsidiary of the multinational automoti ...
's buyout of AMC.
Subaru
( or ; ) is the automaker, automobile manufacturing division of Japanese transportation conglomerate (company), conglomerate Subaru Corporation (formerly known as Fuji Heavy Industries), the Automotive industry#By manufacturer, twenty-first ...
introduced the category-expanding Leone in 1972, an inexpensive compact station wagon
A station wagon ( US, also wagon) or estate car ( UK, also estate), is an automotive body-style variant of a sedan/saloon with its roof extended rearward over a shared passenger/cargo volume with access at the back via a third or fifth door ( ...
with a light-duty, part-time four-wheel-drive system that could not be engaged on dry pavement. In September, AMC introduced Quadra Trac full-time AWD for the 1973 model year Jeep Cherokee and Wagoneer. Due to full-time AWD, which relieved the driver of getting out to lock hubs and having to manually select between 2WD and 4WD modes, it dominated all other makes in FIA rally competition. Gene Henderson and Ken Pogue won the Press-on-Regardless Rally
Press On Regardless (''POR'') is a road rally organized by the Detroit Region of the Sports Car Club of America.
The Press On Regardless was first run in 1949 as a Time-Speed-Distance rally. In 1969, the POR became a stage rally. In 1972, the e ...
FIA championship with a Quadra Trac-equipped Jeep in 1972.
American Motors introduced the innovative Eagle
Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. Most of the 68 species of eagle are from Eurasia and Africa. Outside this area, just ...
for the 1980 model year. These were the first American mass-production cars to use the complete front-engine, four-wheel-drive system. The AMC Eagle was offered as a sedan, coupe
A coupe or coupé (, ) is a passenger car with a sloping or truncated rear roofline and two doors.
The term ''coupé'' was first applied to horse-drawn carriages for two passengers without rear-facing seats. It comes from the French past parti ...
, and station wagon with permanent automatic all-wheel drive passenger models. The new Eagles combined Jeep technology with an existing and proven AMC passenger automobile platform
A car platform is a shared set of common design, engineering, and production efforts, as well as major components, over a number of outwardly distinct models and even types of cars, often from different, but somewhat related, marques. It is pract ...
. They ushered a whole new product category of "sport-utility" or crossover SUV
A crossover, crossover SUV, or crossover utility vehicle (CUV) is a type of automobile with an increased ride height that is built on unibody chassis construction shared with passenger cars, as opposed to traditional sport utility vehicles (S ...
. AMC's Eagles came with the comfort and high-level appointments expected of regular passenger models and used the off-road technology for an extra margin of safety and traction.
The Eagle's thick viscous
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inter ...
fluid center differential provided a quiet and smooth transfer of power that was directed proportionally to the axle with the greatest traction. This was a true full-time system operating only in four-wheel drive without undue wear on suspension or driveline components. No low range was used in the transfer case. This became the forerunner of the designs that followed from other manufacturers. The automobile press at the time tested the traction of the Eagles and described it as far superior to the Subaru's and that it could beat many so-called off-road vehicles. ''Four Wheeler'' magazine concluded that the AMC Eagle was "The beginning of a new generation of cars."
The Eagles were popular (particularly in the snowbelt
The Snowbelt is the region near the Great Lakes in North America where heavy snowfall in the form of lake-effect snow is particularly common. Snowbelts are typically found downwind of the lakes, principally off the eastern and southern shores.
Ca ...
), had towing capacity, and came in several equipment levels including sport and luxury trims. Two additional models were added in 1981, the subcompact SX/4 and Kammback. A manual transmission and a front axle-disconnect feature were also made available for greater fuel economy. During 1981 and 1982, a unique convertible
A convertible or cabriolet () is a passenger car that can be driven with or without a roof in place. The methods of retracting and storing the roof vary among eras and manufacturers.
A convertible car's design allows an open-air driving expe ...
was added to the line. The Eagle's monocoque
Monocoque ( ), also called structural skin, is a structural system in which loads are supported by an object's external skin, in a manner similar to an egg shell. The word ''monocoque'' is a French term for "single shell".
First used for boats, ...
body was reinforced for the conversion and had a steel targa bar with a removable fiberglass roof section. The Eagle station wagon remained in production for one model year after Chrysler acquired AMC in 1987. Total AMC Eagle production was almost 200,000 vehicles.
Audi
Audi AG () is a German automotive manufacturer of luxury vehicles headquartered in Ingolstadt, Bavaria, Germany. As a subsidiary of its parent company, the Volkswagen Group, Audi produces vehicles in nine production facilities worldwide.
Th ...
also introduced a permanently all-wheel-driven road-going car, the Audi Quattro
The Audi Quattro is a road and rally car, produced by the German automobile manufacturer Audi, part of the Volkswagen Group. It was first shown at the 1980 Geneva Motor Show on 3 March. Production continued through 1991.
Background
The word ...
, in 1980. Audi's chassis engineer, Jörg Bensinger
Jörg Bensinger is a German automotive chassis engineer, who pioneered four-wheel drive (all-wheel) transmission for conventional (on-road) automobiles in the 1980s, first developing the idea in 1977.
Career Audi
He joined the R&D department o ...
, had noticed in winter tests in Finland that a vehicle used by the West German Army, the Volkswagen
Volkswagen (),English: , . abbreviated as VW (), is a German Automotive industry, motor vehicle manufacturer headquartered in Wolfsburg, Lower Saxony, Germany. Founded in 1937 by the German Labour Front under the Nazi Party and revived into a ...
Iltis, could beat any high-performance Audi. He proposed developing a four-wheel-drive car that would also be used for rallying
Rally is a wide-ranging form of motorsport with various competitive motoring elements such as speed tests (often called ''rally racing),'' navigation tests, or the ability to reach waypoints or a destination at a prescribed time or average speed. ...
to improve Audi's conservative image. The Audi quattro system became a feature on production cars.
In 1987, Toyota
is a Japanese multinational automotive manufacturer headquartered in Toyota City, Aichi, Japan. It was founded by Kiichiro Toyoda and incorporated on . Toyota is one of the largest automobile manufacturers in the world, producing about 10 ...
also developed a car built for competition in rally campaigns. A limited number of road-going FIA
FIA is the Fédération Internationale de l'Automobile (English: International Automobile Federation), the world's governing body for all forms of motor sport where four or more wheels are used.
Fia or FIA may also refer to: People
* Fia Backst ...
Homologation
Homologation (Greek ''homologeo'', ὁμολογέω, "to agree") is the granting of approval by an official authority. This may be a court of law, a government department, or an academic or professional body, any of which would normally work fr ...
Special Vehicle Celica GT-Four (known as Toyota Celica
The is an automobile produced by Toyota from 1970 until 2006. The Celica name derives from the Latin word '' coelica'' meaning 'heavenly' or 'celestial'. In Japan, the Celica was exclusive to the ''Toyota Corolla Store'' dealer chain.
Produce ...
All-Trac Turbo in North America) were produced. The All-Trac system was later available on serial production Toyota Camry
The Toyota Camry (; Japanese: トヨタ・カムリ ''Toyota Kamuri'') is an automobile sold internationally by the Japanese auto manufacturer Toyota since 1982, spanning multiple generations. Originally compact in size (narrow-body), the Camry ...
, Toyota Corolla
The is a series of compact cars (formerly subcompact) manufactured and marketed globally by the Toyota Motor Corporation. Introduced in 1966, the Corolla was the best-selling car worldwide by 1974 and has been one of the best-selling cars in ...
, and Toyota Previa
The Toyota Previa, also known as the in Japan, and Toyota Tarago in Australia, is a minivan that was produced by Toyota from 1990 until October 2019 across three generations.
The name "Previa" is derived from the Spanish and Italian for "previ ...
models.
Some of the earliest mid-engined
In automotive engineering, a mid-engine layout describes the placement of an automobile engine in front of the rear-wheel axles, but behind the front axle.
History
The mid-engine, rear-wheel-drive format can be considered the original layout of ...
four-wheel-drive cars were the various road-legal rally cars made for Group B
Group B was a set of regulations for grand touring (GT) vehicles used in sports car racing and rallying introduced in 1982 by the Fédération Internationale de l'Automobile (FIA). Although permitted to enter a GT class of the World Sportscar ...
homologation, such as the Ford RS200
The Ford RS200 is a mid-engined, four-wheel drive sports car that was produced by Ford Motorsport in Boreham, UK, from 1984 to 1986. The road-going RS200 was the basis for Ford's Group B rally car and was designed to comply with FIA homologation ...
made from 1984 to 1986. In 1989, niche maker Panther Westwinds
Panther Westwinds (commonly known as Panther) was a manufacturer of niche sports cars and luxury cars, based in Surrey, United Kingdom.
History
Founded in 1972 by Robert Jankel, the Panther company initially manufactured retro-styled cars based ...
created a mid-engined four-wheel drive, the Panther Solo 2.
2000–present
In the United States, as of late 2013, AWD vehicles comprised 32% of new light vehicle sales, up 5% since 2008. This is in large part due to the popularity of the crossover
Crossover may refer to:
Entertainment
Albums and songs
* ''Cross Over'' (Dan Peek album)
* ''Crossover'' (Dirty Rotten Imbeciles album), 1987
* ''Crossover'' (Intrigue album)
* ''Crossover'' (Hitomi Shimatani album)
* ''Crossover'' (Yoshino ...
. Most crossovers offer the popular technology, in spite of it increasing vehicle price and fuel consumption. Car manufacturers have inundated consumers with marketing proclaiming AWD as a safety feature, although the advantage of AWD over FWD occurs in accelerating, not braking or steering. Tests have shown that though AWD gives improved acceleration in wintery conditions, it does not help with braking.
In 2008, Nissan introduced the GT-R featuring a rear-mounted transaxle
A transaxle is a single mechanical device which combines the functions of an automobile's transmission, axle, and differential into one integrated assembly. It can be produced in both manual and automatic versions.
Engine and drive at the ...
. The AWD system requires two drive shaft
A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power (physics), power and torque and rotation, usually ...
s, one main shaft from the engine to the transaxle and differential and a second drive shaft from the transaxle to the front wheels.
Uses
Road racing
Spyker
Spyker or Spijker was a Dutch carriage, automobile and aircraft manufacturer, started in 1880 by blacksmiths Jacobus and Hendrik-Jan Spijker. Originally located in Hilversum, the company relocated to Trompenburg, Amsterdam in 1898.
Notable produ ...
is credited with building and racing the first four-wheel-drive racing car, the Spyker 60 HP in 1903.
Bugatti
Automobiles Ettore Bugatti was a German then French manufacturer of high-performance automobiles. The company was founded in 1909 in the then-German city of Molsheim, Alsace, by the Italian-born industrial designer Ettore Bugatti. The cars w ...
created a total of three four-wheel-drive racers, the Bugatti Type 53, Type 53, in 1932, but the cars were notorious for having poor Automobile handling, handling.
Miller produced the first 4WD car to qualify for the Indianapolis 500, the 1938 Miller Gulf Special.
Ferguson Research Ltd. built the front-engined P99 Formula One car that actually won a non-World Championship race with Stirling Moss in 1961. In 1968, Team Lotus raced cars in the Indy 500 and three years later in Formula 1 with the Lotus 56, that had both turbine engines and 4WD, as well as the 1969 4WD-Lotus 63 that had the standard 3-litre V8 Ford
Ford commonly refers to:
* Ford Motor Company, an automobile manufacturer founded by Henry Ford
* Ford (crossing), a shallow crossing on a river
Ford may also refer to:
Ford Motor Company
* Henry Ford, founder of the Ford Motor Company
* Ford F ...
Cosworth engine. Equipe Matra Sports, Matra also raced a similar MS84, and McLaren (racing), McLaren entered their McLaren M9A, M9A in the 1969 British Grand Prix, British Grand Prix, while engine manufacturers Ford-Cosworth produced their own version, which was tested but never raced. All these F1 cars were considered inferior to their RWD counterparts, as the advent of aerodynamic downforce meant that adequate traction could be obtained in a lighter and more mechanically efficient manner, and the idea was discontinued, though Lotus tried repeatedly.
Nissan and Audi had success with all-wheel drive in road racing with the former's advent of the Nissan Skyline GT-R in 1989. So successful was the car that it dominated the Japanese circuit for the first years of production, going on to bigger and more impressive wins in Australia before weight penalties eventually levied a'' de facto ''ban on the car. Most controversial was the win pulled off at the 1990 Macau Grand Prix, where the car led from start to finish. Audi's dominance in the Trans-Am Series in 1988 was equally controversial, as it led to a weight penalty midseason and to a rule revision banning all AWD cars; its dominance in Super Touring eventually led to a FIA
FIA is the Fédération Internationale de l'Automobile (English: International Automobile Federation), the world's governing body for all forms of motor sport where four or more wheels are used.
Fia or FIA may also refer to: People
* Fia Backst ...
ban on AWD system in 1998.
New 24 Hours of Le Mans regulations may revive AWD/4WD in road racing, though such systems are only allowed in new Hybrid vehicle drivetrain, hybrid-powered Le Mans prototypes. One example is the Audi R18#R18 e-tron quattro, Audi R18 e-tron quattro (winner of race, the first hybrid/4WD to win Le Mans), using an electric motor in the front axle with the gasoline engine in the rear.
In heavy trucks
Truck classification#Medium duty, Medium-duty and Truck classification#Heavy duty, heavy-duty trucks have recently adopted 4×4 drivetrains; 4×4 medium-duty trucks became common after Ford began selling Ford Super Duty trucks. These trucks shared many parts between the light-duty and medium-duty, reducing production costs. The Dana 60 front axle is used on both medium- and light-duty Super Duty trucks. Furthermore, the Big Three (automobile manufacturers), Big Three share/shared parts between the companies, reducing costs. The Dana S 110 is currently being used for the rear drive, under Ford and Ram's medium-duty trucks. The Dana 110 was also used on the General Motors 4×4s. Ram Trucks began selling medium-duty trucks, 4×4 and 4×2, in 2008. General Motors sold a Chevrolet Kodiak, 4×4 for model years 2005–2009.
File:C4500 GM 4x4 Medium duty trucks.jpg, GM 4×4 medium-duty trucks
File:4x4HD International Workstar.jpg, Heavy-duty International Workstar
File:Ford SD medium duty 4x4 drive train.jpg, Ford medium-duty 4×4 drive train
In construction equipment
Volvo introduced the Model 646 four-wheel-drive backhoe loader in 1977. Case CE, Case Corporation followed suit in the U.S. in 1987.
Terminology
In engineering terms, "four-wheel drive" designates a vehicle with power delivered to four wheel ends spread over at least two axles. The term "4×4" (pronounced ''four by four'') was in use to describe North American military four-wheel-drive vehicles as early as the 1940s, with the first number indicating the number of wheel ends on a vehicle and the second indicating the number of driven wheels.
Trucks with dual tires on the rear axle and two driven axles are designated as 4×4s despite having six wheels, because the paired rear wheels behave as a single wheel for traction and classification purposes. True 6×6
Six-wheel drive (6WD or 6×6) is an all-wheel drive drivetrain configuration of three axles with at least two wheels on each axle capable of being driven simultaneously by the vehicle's engine. Unlike four-wheel drive drivetrains, the configurat ...
vehicles, which have three powered axles, are classified as 6×6s regardless of how many wheels they have. Examples of these with two rear, one front axle are the six-wheeled Pinzgauer High Mobility All-Terrain Vehicle, Pinzgauer, which is popular with defense forces around the globe, and 10-wheeled GMC CCKW made famous by the U.S. Army in World War II.
4-wheeler, Four-wheeler is a related term applying to all-terrain vehicles, and not to be confused with four-wheel drive. The "four" in the instance referring to the vehicle having four wheels, not necessarily all driven.
Unusual systems
Prompted by a perceived need for a simple, inexpensive all-terrain vehicle for oil exploration in North Africa, French motor manufacturer Citroën developed the Citroën 2CV, 2CV Sahara in 1958. Unlike other 4×4 vehicles, which use a conventional transfer case
A transfer case is a part of the drivetrain of four-wheel-drive, all-wheel-drive, and other multiple powered axle vehicles. The transfer case transfers power from the transmission to the front and rear axles by means of drive shafts. It also syn ...
to drive the front and rear axles, the Sahara had two engines, each independently driving a separate axle, with the rear engine facing backwards. The two throttles, clutches, and gear-change mechanisms could be linked, so the two engines could run together, or they could be split and the car driven solely by either engine. Combined with twin fuel tanks and twin batteries (which could be set up to run either or both engines), the redundancy of two separate drive trains meant that they could make it back to civilization even after major mechanical failures. Only around 700 of these cars were built, and only 27 are known to exist today.
British Motor Corporation, BMC experimented with a twin-engined Mini Moke (dubbed the "Twini Moke") in the mid-1960s, but never put it into production. This made advantage of the Austin Mini, Mini's 'power pack' layout, with a transverse engine and the gearbox in the engine sump. Simply by fitting a second engine/gearbox unit across the rear, a rudimentary 4×4 system could be produced. Early prototypes had separate gear levers and clutch systems for each engine. Later versions sent for evaluation by the British Army had more user-friendly linked systems.
In 1965, A. J. M. Chadwick patented a 4WD system, GB 1113068, that used hemispherical wheels for an all-terrain vehicle. Twenty years later, B. T. E. Warne, patented, GB 2172558, an improvement on Chadwick's design that did not use differential gear assemblies. By using near-spherical wheels with the provision to tilt and turn each wheel co-ordinatively, the driven wheels maintain constant traction. Furthermore, all driven wheels steer, and as pairing of wheels is not necessary, vehicles with an odd number of wheels are possible without affecting the system's integrity. Progressive deceleration is made possible by dynamically changing the front-to-rear effective wheel diameter ratios.
Suzuki Motors introduced the Suzuki Escudo Pikes Peak Edition in 1996. Earlier Suzuki versions were twin-engined; from 1996 on, the engine is a twin-turbocharged 2.0-L V6, mated to a sequential six-speed manual transmission.
Nissan Motors has developed a system called Nissan E-4WD, E-4WD, designed for cars that are normally front-wheel drive; however, the rear wheels are powered by electric motors. This system was introduced in some variants of the Nissan Cube and Nissan Tiida, Tiida. (This is similar to the system used on the Ford Escape Hybrid AWD.)
Chrysler's Jeep Division debuted the twin-engined, Jeep Hurricane concept at the 2005 North American International Auto Show in Detroit. This vehicle has a unique "crab crawl" capability, which allows it to rotate 360° in place. This is accomplished by driving the left wheels as a pair and the right wheels as a pair, as opposed to driving the front and rear pairs. A central gearbox allows one side to drive in the opposite direction from the other. It also has dual Chrysler Hemi engine, Hemi V8s.
Some hybrid electric vehicle, hybrid vehicles such as the Lexus Lexus RX400h, RX400h provide power to an AWD system through a pair of electric motors, one to the front wheels and one to the rear. In the case of the AWD model version of the Lexus RX400h (and its Toyota-branded counterpart, the Toyota Harrier, Harrier hybrid), the front wheels can also receive drive power directly from the vehicle's gasoline engine, as well as via the electric motors, whereas the rear wheels derive power only from the second electric motor. Transfer of power is managed automatically by internal electronics based on traction conditions and need, making this an all-wheel-drive system.
The 4RM system used in the Ferrari FF in 2011 is unique in that it has a rear transaxle with a secondary front transaxle connected directly to the engine. The car operates primarily as a rear-wheel drive vehicle. Clutches in the front transaxle engage when the rear wheels slip. Drive to the front wheels is transmitted through two infinitely variable clutch packs that are allowed to 'slip' to give the required road wheel speeds. The front transaxle has three gears, two forward, and reverse. The two forward gears of the front transmission match the lower four forward gears of the rear transmission. It is not used in higher gears. The connection between this gearbox and each front wheel is via independent Haldex-type clutches, without a differential. Due to the difference in ratios, the clutches continually slip and only transmit, at most, 20% of the engine's torque.
Systems by design type
Center differential with mechanical lock
* Alfa Romeo 164 Q4 (central viscous coupling, epicyclic unit and Torsen rear differential)
* Alfa Romeo 155 Q4 (central epicyclic unit, Ferguson viscous coupling and Torsen rear differential)
* AMC Eagle (central viscous coupling)
* Audi
Audi AG () is a German automotive manufacturer of luxury vehicles headquartered in Ingolstadt, Bavaria, Germany. As a subsidiary of its parent company, the Volkswagen Group, Audi produces vehicles in nine production facilities worldwide.
Th ...
– Audi Quattro, Quattro Coupé, 80, 90, 100 & 200 (locking center and rear differentials) – up to 1987
* Audi Q7 -double pinion 50/50 with lockup clutch pack
* BMW BMW 3 Series (E30), 3 series and BMW 5 Series (E34), 5 series in the 1980s – planetary center differential with a 37–63 (front-back) torque split and Viscous coupling unit, viscous lock (also in rear differential but not front differential)
* Chevrolet ''Rounded-Line'' Chevrolet C/K#Third generation (1973–1991), K Fleetside, Chevrolet C/K#Third generation (1973–1991), K Stepside, Chevrolet K5 Blazer#1973–1991, K Blazer, and Chevrolet Suburban#Eighth generation (1973–1991), K Suburban – permanent four-wheel-drive (1973–1979) two-speed New Process 203 transfer case, center differential with 50:50 torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
split and lock. An Locking differential#Automatic lockers, ''Eaton Automatic Differential Lock'' was optional for the rear hypoid differential.
* Ford Escort RS (RS 2000 16v 4×4 models and RS Cosworth), Sierra Cosworth, Sierra and Granada 4×4 models,
* Dodge Power Wagon – permanent four-wheel-drive (1974–1979) two-speed New Process 203 transfer case, center differential with 50:50 torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
split and lock.
* Ford Expedition (1997–present) and Ford Expedition#Expedition EL/Max, Expedition EL/Max (2007–present) – automatic Control Trac, ''ControlTrac'' four-wheel drive with two-speed dual range BorgWarner transfer case and Artificial intelligence, intelligent locking center Electromagnetic clutch#Multiple disk clutches, multi-disc differential
* Ford Explorer (1995–2010) – automatic ''ControlTrac'' four-wheel drive with two-speed dual range BorgWarner transfer case and intelligent locking center multi-disc differential
* Ford F-Series – permanent four-wheel-drive (1974–1979) two-speed New Process 203 transfer case, center differential with 50:50 torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
split and lock.
* GMC (automobile), GMC ''Rounded-Line'' Chevrolet C/K#Third generation (1973–1991), K Wideside, Chevrolet C/K#Third generation (1973–1991), K Fenderside, Chevrolet K5 Blazer#1973–1991, K Jimmy, and Chevrolet Suburban#Eighth generation (1973–1991), K Suburban – permanent four-wheel-drive (1973–1979) two-speed New Process 203 transfer case, center planetary differential with 50:50 torque split and lock. An ''Eaton Automatic Differential Lock'' was optional for the rear hypoid differential.
* H1 & Humvee NVG 242HD AMG open center differential, locked center differential, Neutral, low range locked. Also Torsen, Torsen1 differential at the front and rear axle, The H1 moved to Torsen2 when ABS was added. The H1 Alpha had optional locking differentials in place of torsens.
* Hummer H2, H3 40/60 planetary with lock
* Jeep Grand Cherokee, Commander (except models equipped with Quadra-Trac I)
* Jeep Liberty, Jeep Cherokee (XJ), Dodge Durango (Jeep four-wheel-drive systems, Select-Trac) – NV 242 transfer case- rear drive, open center differential, locked center differential, Neutral, low range
* Jeep SJ, Full size Jeeps with Borg Warner QuadraTrac: limited-slip center differential, 50/50 locked center differential. Low range could be used in locked or unlocked mode, allowing for use of the low range on pavement.
* Land Rover Defender (and Land Rover Series, Series III Rover V8 engine, V8 models)
* Land Rover Discovery/LR3
* Land Rover Freelander
* Lada Niva (VAZ-2121) – full-time 4WD using open center differential. Transfer case with high/low range and manual central diff lock. Low range selectable in locked or unlocked mode, allowing use on pavement.
* Lexus RX300 -viscous coupling unit, viscous coupling across the otherwise open center differential.
* Lincoln Navigator (1998–2006) – automatic ''ControlTrac'' four-wheel drive with two-speed dual range BorgWarner transfer case and intelligent locking center multi-disc differential
** Navigator and Navigator L (2007–present) use a one-speed single range transfer case, no reduction gearing
* Mercedes-Benz Unimog
The Unimog (, ) is a range of multi-purpose tractors, trucks and lorries that has been produced by Boehringer from 1948 until 1951, and by Daimler Truck (formerly Daimler-Benz, DaimlerChrysler and Daimler AG) since 1951. In the United States and ...
(locking center and rear with up to 10 low range gears).
* Mercedes-Benz G-Class (locking center and lockers on both front- and rear axle)
* Mercedes-Benz GL-Class – 4Matic all-wheel-drive system
* Mitsubishi Pajero (also known as Montero or Shogun)
* Porsche Cayenne – 38/62 planetary with lockup clutch pack
* Range Rover
Range may refer to:
Geography
* Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra)
** Mountain range, a group of mountains bordered by lowlands
* Range, a term used to i ...
Classic 1970–1995 all full-time 4WD either plate LSD, manual lock or Ferguson viscous center differential.
* Range Rover 2nd Gen. 1994–2002 full-time 4WD Ferguson viscous center differential
* Suzuki Grand Vitara/Escudo (2005 and later models, excepting the XL-7) -full-time 4WD using limited-slip center differential, off-road 4WD with selectable center differential lock and low range transfer case 4 mode (4h, 4h lock, 4l n), traction control system, traction control and electronic stability control
* Subaru
( or ; ) is the automaker, automobile manufacturing division of Japanese transportation conglomerate (company), conglomerate Subaru Corporation (formerly known as Fuji Heavy Industries), the Automotive industry#By manufacturer, twenty-first ...
– manual transmissions come with 50/50 viscous-type center differential; performance models include a planetary differential with computer-regulated lockup; automatic transmission models have an electronically controlled variable transfer clutch.
* Toyota Land Cruiser
* Toyota Sequoia (Multi-mode)
* Volkswagen Touareg -double pinion 50/50 with lockup clutch pack
Torsen center differential
* Alfa Romeo Q4s – with (Torsen
Torsen Torque-Sensing (full name Torsen traction) is a type of limited-slip differential used in automobiles.
It was invented by American Vernon Gleasman and manufactured by the Gleason Corporation. Torsen is a portmanteau of Torque-Sensing. ''TO ...
T-3):
** Alfa Romeo 156, 156 Crosswagon and Sportwagon
** Alfa Romeo 159, 159
** Alfa Romeo Brera, Brera, Alfa Romeo Brera, Spider
* Audi
Audi AG () is a German automotive manufacturer of luxury vehicles headquartered in Ingolstadt, Bavaria, Germany. As a subsidiary of its parent company, the Volkswagen Group, Audi produces vehicles in nine production facilities worldwide.
Th ...
s with quattro (four-wheel-drive system), quattro – various iterations of Torsen, the T-3 starting from the 2007 Audi RS4, B7 RS4
** Audi 80, 80, 90 & Coupé (Typ 89)
** Audi 100, 100 & 200
** Audi A4, A4, Audi S4, S4, Audi RS4, RS4
** Audi A5, A5 & S5
** Audi A6, A6, Audi S6, S6, Audi RS6, RS6
** Audi A8, A8, Audi S8, S8
** Q5, Audi Q7, Q7
* Bentley Continental GT, Bentley Continental Flying Spur (2005) initially Torsen T-2, current have T-3
* Chevrolet Trailblazer (Mid-size SUV), Chevrolet Trailblazer SS Torsen T-3
* Lexus GX470, Toyota Land Cruiser Prado 120 Torsen T-3
*Range Rover 3rd Gen. 2002–2009
* Toyota 4Runner (Only 2003-2009 model and 2010+ Limited V6 model) Torsen T-3 with lock
* Toyota FJ Cruiser (only manual models) Torsen T-3 with lock
* Toyota Hilux Surf Torsen T-3 with lock
* Toyota Land Cruiser 200/2008/V8 Torsen T-3 with lock
* Toyota Sequoia (only 2005–07 Models)
* Volkswagen, Volkswagen Passenger Cars with 4motion:
** Volkswagen Passat Torsen T-2 (B5.5 model, not latest B6 model with transverse engine)
** Volkswagen Phaeton Torsen T-2
Non-locking center differential
* BMW BMW 3 Series (E46), 3-series and BMW X5 (E53), X5 between 2001 and BMW xDrive, xDrive – planetary center differential with permanent 38–62 (front-back) torque split #
* Cadillac Escalade, STS AWD, SRX AWD (The first two generations had a viscous clutch on the center differential) #
* Chrysler 300C AWD#
* Dodge Ramcharger 1974–1981 – NP203 FullTime 4WD Transfer Case
* Dodge Magnum, Charger AWD #
* GMC Yukon Denali, XL Denali, Sierra Denali #
* Mercedes 4MATIC cars, R class, and ML class (note some MLs had low range) #
* Plymouth Trail Duster 1974–1981 – NP203 FullTime 4WD Transfer Case
* Toyota Highlander #
* Toyota Sienna AWD (−2010 only) #
The above systems ending with "#" function by selectively using the traction control system (via ABS) to brake a slipping wheel.
Multiple-clutch systems
* Acura RL, RDX (SH-AWD) Right and left axle shaft
* Acura MDX SH-AWD & VTM4
* Ford Explorer#Fifth generation (U502; 2011), Ford Explorer – Ford's full-time shift-on-the-fly ''Intelligent 4WD System'' (I-4WD) on the 2011 Explorer with ''Terrain Management System'' and RSC (Roll Stability Control), Curve Control functionality, HDC (Hill Descent Control) and HAA (Hill Ascent Assist).
* Honda Ridgeline
* Honda Pilot
* Infiniti FX (ATTESA, ATTESA E-TS)
* Mercedes-Benz 1st generation 4Matic, 4MATIC (normally rear-drive, automatic clutch in transfer case engages 4WD on demand)
* Mitsubishi GTO MR/3000GT VR-4
* Mitsubishi Lancer Evolution Series Mitsubishi S-AWC, S-AWC
* 2010 Mitsubishi Outlander GT Mitsubishi S-AWC, S-AWC
* Mitsubishi Outlander (2003–2006) independent front and rear axle coupling, and Active Center Differential.
* Nissan GT-R (ATTESA, ATTESA E-TS)
* Nissan Skyline GT-R (ATTESA, ATTESA E-TS and ATTESA, ATTESA E-TS-PRO) front axle coupling, rear differential locking
* Nissan Skyline GTS4 (ATTESA E-TS)
* Nissan A31 Cefiro SE4 (ATTESA E-TS)
* Porsche 959 PSK front axle coupling, rear differential locking
* Saab 9-3, Saab 9-5, Saab 9-4X (Saab XWD)
Multi-plate clutch coupling
* Audi A3 quattro, Audi S3, Audi TT quattro, Audi R8 (road car), Audi R8 (with Haldex Traction)
* BMW BMW xDrive, xDrive: BMW 3 Series (E90), latest 3 Series, BMW 5 Series (E60), latest 5 series, X3, BMW X5 (E70), latest X5 series
* Chevrolet Equinox (GMPCA)
* Chrysler Pacifica (BorgWarner ITM3e) (on 2007 model)
* Dodge Nitro (Quadra-Trac 1)
* Dodge Caliber
* Ford
Ford commonly refers to:
* Ford Motor Company, an automobile manufacturer founded by Henry Ford
* Ford (crossing), a shallow crossing on a river
Ford may also refer to:
Ford Motor Company
* Henry Ford, founder of the Ford Motor Company
* Ford F ...
: Escape, Freestyle, Edge, Fusion, Five Hundred (Freestyle, FiveHundred Haldex Traction based) (Escape Control Trac II, based)
* Honda CR-V, HR-V, Element
* Hyundai Santa Fe, Hyundai Tucson Borg-Warner ITM 3e magnetic multi-plate clutch coupling
* Hyundai Veracruz IMJ magnetic multi-plate clutch coupling
* Infiniti: G35x, M35x
* Jeep Compass (Freedom Drive)
* Jeep Grand Cherokee and SRT8 NVG 249, 247
* Land Rover Freelander, Land Rover Freelander 2/LR2 (also Haldex Traction)[According to Car and Driver Vol52 No 8, February 2007, page 110]
* Lamborghini: AWD variants VT series (viscous traction)
* Lincoln (automobile), Lincoln: MKS, MKZ
* Mazdaspeed6 (a power takeoff unit linked to clutch pack with torque sensitive rear differential)
* Mazda: Mazda3, Mazdaspeed6, Tribute, CX-3, CX-30, CX-5, CX-50, CX-60, CX-7, CX-8, CX-9 (tribute Control Trac II, based)
* Mercury (automobile), Mercury: Milan, Montego, Mariner (Montego Haldex Traction–based)
* Mitsubishi Outlander (current generation)
* Nissan Murano automatic with manual lockup switch
* Porsche 911 AWD variants (a version of BorgWarner ITM3e) — excluding the 964-series Porsche 911 Carrera 4 31/69 planetary center differential
* Pontiac Torrent (GMPCA)
* Subaru
( or ; ) is the automaker, automobile manufacturing division of Japanese transportation conglomerate (company), conglomerate Subaru Corporation (formerly known as Fuji Heavy Industries), the Automotive industry#By manufacturer, twenty-first ...
low powered automatic transmission models
* Subaru Legacy, Subaru Outback, Outback, Subaru Impreza, Impreza, Subaru Forester, Forester, Subaru Tribeca, Tribeca automatic transmission models: mechanical front drive, clutch coupled rear axle
* Suzuki: SX4, XL7, Aerio, Swift/Cultus based Subaru Justy. (viscous clutch)
* Toyota RAV4 – from 2005 (third generation only)
* Toyota Sienna AWD (2011 and newer only)
* Volkswagen Golf 4motion, Volkswagen Jetta 4motion, Volkswagen Tiguan 4motion, Volkswagen Passat (B6) 4motion (initially viscous coupling, later with Haldex Traction)
* Volvo: S40, S60, S80, V50, V70, XC70, XC90 (Visco system until 2003; then all Haldex Traction–based)
Note: the above all function like 2WD when the multi-plate clutch coupling is not engaged (with exception of Subaru models), and like 4WD high-range in a part-time 4WD system when the clutch is engaged (usually by computer although some allow manual control). Some in this category have varying degrees of control in the torque distribution between front and rear by allowing some of the clutches in a multi-plate clutch coupling to engage and slip varying amounts. An example of a system like this is the BorgWarner i-Trac(TM) system.
Note: the Haldex Traction-based car list was created from the list on Haldex Traction corporate website
Haldex Cars
A version of the BorgWarner ITM3e system is used on 2006 and up Porsche 911TT's. The Borg-Warner ITM 3e is also used in the 2006-now Hyundai Santa Fe and the Hyundai Tucson. In the Hyundais, the ITM 3e acts like a full-time AWD with 95:5 normal torque split. In extreme conditions, the system can be locked in a 50:50 split via the 4WD LOCK button.
Part-time
These are vehicles that have no center differential. Since there is no center differential to allow for speed differences between the front and rear wheels when turning, a small amount of tire slippage must occur during turns. When used on slick surfaces, this is not a problem, but when turning on dry pavement, the tires grip, then are forced to slip, then grip again, and so on, until the turn is completed. This causes the vehicle to exhibit a 'hopping' or 'binding' sensation. Using an engaged part-time 4WD system on a hard surface is not recommended, as damage to the drive-line eventually occurs. Part-time transfer cases are the industry standard transfer case for the 4x4 truck market. Any other transfer case can be considered more robust, however more moving parts and complexity can, sometimes, make other transfer cases less durable.
See also
* 4WS
* Dune bashing
* Four-wheel drive in Formula One
* Limited slip differential
* Off-road vehicle
* Rock crawling
* Sport utility vehicle
* Transfer case
* Driveline windup
Footnotes
References
{{DEFAULTSORT:Four-Wheel Drive
Off-road vehicles
Car layouts
Drivetrain
Four-wheel drive layout, *
All-wheel-drive vehicles
English inventions
British inventions
af:Motordryfuitleg