automotive design Automotive design is the process of developing the appearance (and to some extent the ergonomics) of motor vehicles - including automobiles, motorcycles, trucks, buses, coaches, and vans. The functional design and development of a modern moto ...

, a front-engine, front-wheel-drive (FWD) layout, or FF layout, places both the

internal combustion engine An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combus ...

and driven roadwheels at the front of the vehicle.

Usage implications

Historically, this designation was used regardless of whether the entire engine was behind the front axle line. In recent times, the manufacturers of some cars have added to the designation with the term '' front-mid'' which describes a car in which the engine is in front of the passenger compartment but behind the front axle. The engine positions of most pre– World-War-II cars are ''front-mid'' or on the front

axle An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearing ...

. This layout is the most traditional form and remains a popular, practical design. The engine, which takes up a great deal of space, is packaged in a location passengers and luggage typically would not use. The main deficit is

weight distribution Weight distribution is the apportioning of weight within a vehicle, especially cars, airplanes, and trains. Typically, it is written in the form ''x''/''y'', where ''x'' is the percentage of weight in the front, and ''y'' is the percentage in the ...

—the heaviest component is at one end of the vehicle.

Car handling Automobile handling and vehicle handling are descriptions of the way a wheeled vehicle responds and reacts to the inputs of a driver, as well as how it moves along a track or road. It is commonly judged by how a vehicle performs particularly durin ...

is not ideal, but usually predictable. In contrast with the front-engine, rear-wheel-drive layout (RWD), the FWD layout eliminates the need for a central tunnel or a higher chassis clearance to accommodate a

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 connec ...

providing power to the rear wheels. Like the

rear-engine, rear-wheel-drive layout In automotive design, an RR, or rear-engine, rear-wheel-drive layout places both the engine and drive wheels at the rear of the vehicle. In contrast to the RMR layout, the center of mass of the engine is between the rear axle and the rear bumpe ...

(RR) and rear mid-engine, rear-wheel-drive layout (RMR) layouts, it places the engine over the drive wheels, improving traction in many applications. As the steered wheels are also the driven wheels, FWD cars are generally considered superior to RWD cars in conditions in which there is low traction such as snow, mud, gravel or wet tarmac. When hill climbing in low-traction conditions RR is considered the best two-wheel-drive layout, primarily due to the shift of weight to the rear wheels when climbing. The cornering ability of a FWD vehicle is generally better, because the engine is placed over the steered wheels. However, as the driven wheels have the additional demands of steering, if a vehicle accelerates quickly, less grip is available for cornering, which can result in

understeer Understeer and oversteer are vehicle dynamics terms used to describe the sensitivity of a vehicle to steering. Oversteer is what occurs when a car turns (steers) by more than the amount commanded by the driver. Conversely, understeer is what occ ...

. High-performance vehicles rarely use the FWD layout because weight is transferred to the rear wheels under acceleration, while unloading the front wheels and sharply reducing their grip, effectively putting a cap on the amount of power which could realistically be utilized; in addition, the high power of high-performance cars can result in

torque steer 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 the ...

. Electronic traction control can avoid wheel-spin but largely negates the benefit of extra power. This was a reason for the adoption of the all-wheel-drive quattro system in the high performance

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 ...

and

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 wo ...

road cars.

Historical arrangements

Early cars using the FWD layout include the 1925 Alvis, 1929

Cord L-29 Cord was the brand name of an American luxury automobile company from Connersville, Indiana, manufactured by the Auburn Automobile Company from 1929 to 1932 and again in 1936 and 1937. The Cord Corporation was founded and run by E. L. Cor ...

, 1931

DKW F1 The DKW F1 was a small car produced by DKW (part of the Auto Union) between 1931 and 1932. It was launched at the Berlin Motor Show in February 1931. Oswald, Werner: Deutsche Autos 1920-1945, volume 2, p. 94: ''"Innerhalb von 6 Wochen sollten nic ...

, the 1948

Citroën 2CV The Citroën 2CV (french: link=no, deux chevaux(-vapeur), , lit. "two steam horse(power)s", meaning "two ''taxable'' horsepower") is an air-cooled front-engine, front-wheel-drive, economy family car, introduced at the 1948 Paris Mondial d ...

, 1949

Saab 92 The Saab 92 was the first production car from Saab Automobile, Saab. The design was very aerodynamic for its time, with a drag coefficient (''cx'' or ''cw'') of 0.30. The entire body was stamped out of one piece of sheet metal and then cut to ac ...

, the 1957 Trabant P50, and the 1959

Mini The Mini is a small, two-door, four-seat car, developed as ADO15, and produced by the British Motor Corporation (BMC) and its successors, from 1959 through 2000. Minus a brief hiatus, original Minis were built for four decades and sold during ...

. In the 1980s, the traction and packaging advantages of this layout caused many compact and mid-sized vehicle makers to adopt it in the US. Most European and Japanese manufacturers switched to front wheel drive for the majority of their cars in the 1960s and 1970s, the last to change being VW, Ford of Europe, and General Motors (Vauxhall - UK and Opel - Germany). Toyota was the last Japanese company to switch in the early 1980s. BMW, focused on luxury vehicles, however retained the rear-wheel-drive layout in even their smaller cars, though their

MINI The Mini is a small, two-door, four-seat car, developed as ADO15, and produced by the British Motor Corporation (BMC) and its successors, from 1959 through 2000. Minus a brief hiatus, original Minis were built for four decades and sold during ...

marque are FWD. There are four different arrangements for this basic layout, depending on the location of the engine, which is the heaviest component of the drivetrain.

Mid-engine / Front-wheel drive

The earliest such arrangement was not technically FF, but rather

mid-engine, front-wheel-drive layout In automotive design, a front-mid-engine, front-wheel-drive layout (also called more simply "mid-engine, front-wheel-drive layout", and abbreviated MF or FMF) is one in which the front road wheels are driven by an internal-combustion engine place ...

(MF). The engine was mounted longitudinally (fore-and-aft, or north–south) behind the wheels, with the transmission ahead of the engine and differential at the very front of the car. With the engine so far back, the weight distribution of such cars as the Cord L-29 was not ideal; the driven wheels did not carry a large enough proportion of weight for good traction and handling. The 1934 Citroën Traction Avant solved the weight distribution issue by placing the transmission at the front of the car with the differential between it and the engine. Combined with the car's low slung

unibody A vehicle frame, also historically known as its '' chassis'', is the main supporting structure of a motor vehicle to which all other components are attached, comparable to the skeleton of an organism. Until the 1930s, virtually every car ha ...

design, this resulted in handling which was remarkable for the era.

Renault Groupe Renault ( , , , also known as the Renault Group in English; legally Renault S.A.) is a French multinational automobile manufacturer established in 1899. The company produces a range of cars and vans, and in the past has manufactured ...

is the most recent user of this format - having used it on the

Renault 4 The Renault 4, also known as the 4L (pronounced "Quatrelle" in French), is a small economy car produced by the French automaker Renault between 1961 and 1994. Although the Renault 4 was marketed as a short station wagon, its minimal rear overhang ...

, and the first generation Renault 5, but it has since fallen out of favor since it encroaches into the interior space.

Longitudinally mounted front-engine and front-wheel drive

The 1946

Panhard Dyna X The Panhard Dyna X was a lightweight berline designed by the engineer Jean Albert Grégoire and first exhibited as the AFG ''(Aluminium Français Grégoire)'' Dyna at the Paris Motor Show in 1946. Conception and development Mindful of the preca ...

, designed by

Jean-Albert Grégoire Jean-Albert Grégoire (7 July 1899 in Paris – 19 August 1992) was one of the great pioneers of the front-wheel-drive car. He contributed to the development of front-wheel-drive vehicles in two ways. The first way was in developing and promoting ...

, had the engine longitudinally in front of the front wheels, with the transmission behind the engine and the differential at the rear of the assembly. This arrangement, used by Panhard until 1967, potentially had a weight distribution problem analogous to that of the Cord L29 mentioned above. However, the Panhard's air-cooled flat twin engine was very light, and mounted low down with a low centre of gravity reducing the effect. The air-cooled flat twin engine of the Citroën 2CV was also mounted very low, in front of the front wheels, with the transmission behind the axle line and the differential between the two. This became quite popular; cars using this layout included the German Ford Taunus 12M and the

Lancia Flavia The Lancia Flavia (Tipo 815/819/820) is an executive car produced by Lancia in Italy from 1961 to 1971. Production continued as the Lancia 2000 from 1971 to 1975. The Flavia was launched with a 1,500 cc engine at the 1960 Turin Motor Sho ...

and

Fulvia Fulvia (; c. 83 BC – 40 BC) was an aristocratic Roman woman who lived during the Late Roman Republic. Fulvia's birth into an important political dynasty facilitated her relationships and, later on, marriages to Publius Clodius Pulcher, Gai ...

. This is the standard configuration of Audi and Subaru front-wheel-drive vehicles. In 1979,

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 ...

introduced and launched their first front-wheel-drive car, the Tercel, and it had its engine longitudinally mounted, unlike most other front-wheel-drive cars on the market at that time. This arrangement continued also on the second-generation Tercel, until 1987, the third generation received a new, transversely mounted engine. Other front-wheel-drive Toyota models, such as

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 ...

, and Corolla, had transversely mounted engines from the beginning on. The 1966

Oldsmobile Toronado The Oldsmobile Toronado is a personal luxury car manufactured and marketed by the Oldsmobile division of General Motors from 1966 to 1992 over four generations. The Toronado was noted for its transaxle version of GM's Turbo-Hydramatic transmissio ...

(along with its sister model the

Cadillac Eldorado The Cadillac Eldorado is a luxury car manufactured and marketed by Cadillac from 1952 until 2002 over twelve generations. The Eldorado was at or near the top of the Cadillac line. The original 1953 Eldorado convertible and the Eldorado Brougham ...

) used a novel arrangement which had the engine and transmission in a 'side-by-side' arrangement with power being transmitted between the two via a heavy-duty chain, and a specially designed intermediate driveshaft that passed under the engine sump. This family has the distinction of being the highest engine capacity (8.2 L) front-wheel-drive vehicles ever built. The

Saab 99 The Saab 99 is a car which was produced by Saab from 1968 to 1984; their first foray into a larger class than the 96. While considered a large family car in Scandinavia, it was marketed as a niche compact executive car in most other markets. It ...

and “classic” Saab 900 also used a similar arrangement. The Eagle Premier used a similar powertrain arrangement found in the Renault 21 and 25 – later becoming the basis for the Chrysler LH sedans produced until the 2004 model year. Today,

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 ...

is the most prominent user of this mechanical layout, having used it since the 1950s in its predecessor companies DKW and

Auto Union Auto Union AG, was an amalgamation of four German automobile manufacturers, founded in 1932 and established in 1936 in Chemnitz, Saxony. It is the immediate predecessor of Audi as it is known today. As well as acting as an umbrella firm fo ...

, and it can be found in its larger models from the A4 upward. The latest evolution of the format in Audi's MLB platform attempts to address the long-standing drawback of uneven weight distribution. This is done by packaging the differential in front of the clutch, allowing the axle line to be further forward in relation to the rear face of the engine block. ----

Front-engine transversely mounted / Front-wheel drive

The first popular transverse engined FWD cars were the DKW 'Front' made from 1931, which had a twin cylinder two-stroke engine. Saab copied this design on their first car, the 1949

. The Trabant in 1957 was also one of the only cars to have a transverse mounted engine, being a sort of DKW successor. This was a novelty, especially for a car being made in a communist country. Issigonis's

of 1959 and related cars such as the Maxi, Austin 1100/1300 and

Allegro Allegro may refer to: Common meanings * Allegro (music), a tempo marking indicate to play fast, quickly and bright * Allegro (ballet), brisk and lively movement Artistic works * L'Allegro (1645), a poem by John Milton * ''Allegro'' (Satie), an ...

had the four-cylinder inline water-cooled engine transversely mounted. The transmission was located in the sump below the crankshaft, with power transmitted by transfer gears. Other models that used the "transmission-in-sump" layout included the Datsun 100A (Cherry) and various applications of the

PSA-Renault X-Type engine The PSA X engine is a family of internal combustion engines used in Citroën, Peugeot, Talbot and Renault automobiles. The X family was mainly used in superminis and the entry level models of midsize vehicles. It was designed and manufactured b ...

such as the

Peugeot 104 The Peugeot 104 is a supermini designed by Paolo Martin and produced by the French car manufacturer Peugeot between 1972 and 1988. It was the first model produced at the company's Mulhouse plant. It was also the first new Peugeot introduced sin ...

and

Renault 14 The Renault 14 is a compact car produced by the French manufacturer Renault between 1976 and 1983. It was first shown in January 1976 with production beginning in June of that year. It was the first car to be produced in large volumes at the compa ...

. The 1955

Suzuki Suzulight Suzulight was the brand used for kei cars built by the Suzuki Motor Corporation from 1955 to 1969. They were Suzuki's first entry into automotive manufacturing, having previously only produced motorcycles. The Suzulight sedans and light vans all h ...

also introduced a front engine with a transversely installed two-stroke twin-cylinder engine (using DKW technology) in a

city car The A-segment is the 1st category in the passenger car classification system defined by the European Commission. It is used for city cars, the smallest category of passenger cars defined. A-segment sales represent approx. 7-8% of the market in ...

/''

kei Kei may refer to: People * Kei (given name) * Kei, Cantonese for Ji (surname), Ji(姫) * Kei, Cantonese for Qi (surname), Qi(奇, 祁, 亓) * Shō Kei (1700–1752), king of the Ryūkyū Kingdom * Kei (singer) (born 1995), stage name of South Kor ...

'' car application, based on the German Lloyd LP400.

Dante Giacosa Dante Giacosa (3 January 1905 - 31 March 1996) was an Italians, Italian automobile designer and engineer responsible for a range of Italian automobile designs — and for refining the front-wheel drive layout to an industry-standard configurati ...

's Autobianchi Primula of 1964, Fiat 128 and

Fiat 127 The Fiat 127 is a supermini car produced by Italian car manufacturer FIAT from 1971 to 1983. It was introduced in 1971 as the replacement for the Fiat 850. Production of the 127 in Italy ended in 1983 following the introduction of its replacemen ...

, put the transmission on one side of the transversely mounted engine, and doubled back the drivetrain to put the differential just behind the transmission, but offset to one side. Hence the driveshafts to the wheels are longer on one side than the other. This located the weight just a bit in front of the wheels. It is this system which dominates worldwide at present. Front-wheel-drive vehicles tend to suffer from ''

'' under heavy acceleration. This is caused by differing drive shaft lengths which in turn results in different incident angles at the joints of the driveshaft. The farther these joints are articulate, the less effective they are at delivering torque to the wheels.

Front-wheel drive design characteristics

Image:R4 1987 1.jpg, Mid-engine, front-wheel drive (

MF layout In automotive design, a front-mid-engine, front-wheel-drive layout (also called more simply "mid-engine, front-wheel-drive layout", and abbreviated MF or FMF) is one in which the front road wheels are driven by an internal-combustion engine place ...

mid-engine, front-wheel-drive layout allows greater distance between front doors and wheelwells, and short front overhang. Image:AutoUnion (DKW) 1000 (registered 1965) right.jpg, Longitudinally front-mounted engine, front-wheel drive (FF longitudinal layout): The

Auto Union 1000 The Auto Union 1000 is a luxury compact front-wheel drive automobile manufactured by Auto Union GmbH between 1958 and 1965. It was the first (and in many markets the last) model branded as an Auto Union by the manufacturer since the 1930's; it ...

, (today Audi) longitudinal layout superseded the

DKW F89 The DKW Meisterklasse (English: "Master Class"), also known as the DKW F89, is a compact car, compact front-wheel drive automobile, saloon manufactured by ''Auto Union Gesellschaft mit beschränkter Haftung, GmbH'' between 1950 and 1954. It was t ...

front transverse engines in the 1950s. Image:Fiat 128 Rally 1972.jpg, Transverse front-mounted engine, front-wheel drive (FF transverse layout): Fiat 128, followed the footsteps of the Autobianchi Primula.

Front-wheel drive shafts

In front wheel drive vehicles, the drive shafts transfer the drive directly from the differential to the front wheels. A short inner stub shaft is splined to the differential side gear and an outer stub shaft is splined to the front wheel hub. Each stub shaft has a yoke, or housing, to accommodate a

universal joint A universal joint (also called a universal coupling or U-joint) is a joint or coupling connecting rigid shafts whose axes are inclined to each other. It is commonly used in shafts that transmit rotary motion. It consists of a pair of hinges ...

, at each end of a connecting intermediate shaft. Universal joints let the shaft keep rotating while allowing for changes due to suspension movement, such as shaft length and horizontal angle, and shaft angle as the steering turns. Constant-velocity universal joints are normally used to transfer power smoothly between the components. The inner universal can be a plunge or tripod type joint. The tripod is splined to the intermediate shaft and held by a circlip. A ball, supported on needle roller bearings, is fitted to each post of the tripod, and these slide in a trunion inside the yoke. This caters for changes in shaft length and horizontal angle. The drive is transferred through the trunion and balls to rotate the shaft. The outer universal joint allows greater angular changes but not changes in shaft length. It is normally a ball and cage type with an inner race splined to the intermediate shaft. An outer race is formed in the yoke. The cage retains the balls in location in grooves in both races. The balls transfer the drive from the shaft to the hub and allow for changes in horizontal angle and for a wide steering angle to be achieved. A flexible rubber boot fitted to each joint retains grease and keeps out dirt and moisture. Where the differential is not located in the center line of the vehicle, an intermediate shaft can be fitted to maintain equal length drive shafts on each side. This keeps drive shaft angles equal on both sides and helps prevent steering irregularities and vibration. The outer end of the intermediate shaft is supported by a bearing secured to the transaxle case and a universal joint assists with alignment. In some cases a longer drive shaft is used on one side. A rubber dynamic damper may be fitted to absorb vibrations.