In automotive engineering, a longitudinal engine is an

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 ...

in which the crankshaft is oriented along the long axis of the

vehicle A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles (trains, trams), ...

, front to back.

Use

This type of motor is usually used for rear-wheel drive cars, except for some

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 ...

and

SAAB Saab or SAAB may refer to: Brands and enterprises * Saab Group, a Swedish aerospace and defence company, formerly known as SAAB, and later as Saab AB ** Datasaab, a former computer company, started as spin off from Saab AB * Saab Automobile, a fo ...

models equipped with longitudinal engines in front wheel drive. In front-wheel drive cars a

transverse engine A transverse engine is an engine mounted in a vehicle so that the engine's crankshaft axis is perpendicular to the direction of travel. Many modern front-wheel drive vehicles use this engine mounting configuration. Most rear-wheel drive vehicles ...

is usually used. Trucks often have longitudinal engines with rear-wheel drive. For motorcycles, the use of a particular type depends on the drive: in case of a chain or belt drive a transverse engine is usually used, and with shaft drives a longitudinal engine. Longitudinal engines in motorcycles do have one disadvantage: the "tipping point" of the crankshaft tilts along the entire motorcycle to a greater or lesser degree when accelerating. This is partly resolved by having other components, such as the generator and the gearbox, rotate in the opposite direction to the crankshaft. Most larger, "premium" vehicles use this engine orientation, both front and

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 ...

n, because powerful engines such as the inline-6 and 90° big-bore V8 are usually too long to fit in a FF transverse engine bay, while most mainstream modern vehicles use

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 longitu ...

along with a transverse engine arrangement. Cars with longitudinal engines usually have a smaller minimum turning circle than those with transverse engines. This is because there is more space to the sides of the engine, allowing deeper wheel arches so the front wheels are able to turn through a greater angle. In the late 1960s, GM divisions Oldsmobile and Cadillac had front-wheel drive models Toronado and

Eldorado El Dorado (, ; Spanish for "the golden"), originally ''El Hombre Dorado'' ("The Golden Man") or ''El Rey Dorado'' ("The Golden King"), was the term used by the Spanish in the 16th century to describe a mythical tribal chief (''zipa'') or king o ...

respectively, with a longitudinal V8 engine and an integrated automatic transmission and differential unit powering the front wheels. Honda and Toyota also offered front-wheel drive cars with longitudinal engines, namely

Honda Vigor The is a premium sedan that was derived from the Honda Accord. It was sold in Japan through the '' Honda Verno'' dealer network from 1981 until 1995, and sold in North America from June 1991 (model year 1992) until 1994 as the Acura Vigor. Early ...

, Acura/Honda Legend/RL, and

Toyota Tercel The is a subcompact car manufactured by Toyota from 1978 until 1999 across five generations, in five body configurations sized between the Corolla and the Starlet. Manufactured at the Takaoka plant in Toyota City, Japan, and sharing its plat ...

Common types

This is a list of typical examples of types of engines which can be placed in motor vehicles: * In-line or straight engine – where

two 2 (two) is a number, numeral and digit. It is the natural number following 1 and preceding 3. It is the smallest and only even prime number. Because it forms the basis of a duality, it has religious and spiritual significance in many cultur ...

three 3 is a number, numeral, and glyph. 3, three, or III may also refer to: * AD 3, the third year of the AD era * 3 BC, the third year before the AD era * March, the third month Books * '' Three of Them'' (Russian: ', literally, "three"), a 1901 ...

four 4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5. It is the smallest semiprime and composite number, and is considered unlucky in many East Asian cultures. In mathematics Four is the smallest c ...

five 5 is a number, numeral, and glyph. 5, five or number 5 may also refer to: * AD 5, the fifth year of the AD era * 5 BC, the fifth year before the AD era Literature * ''5'' (visual novel), a 2008 visual novel by Ram * ''5'' (comics), an awa ...

six 6 is a number, numeral, and glyph. 6 or six may also refer to: * AD 6, the sixth year of the AD era * 6 BC, the sixth year before the AD era * The month of June Science * Carbon, the element with atomic number 6 * 6 Hebe, an asteroid People ...

, and even eight cylinders are placed in a single plane. *

V engine A V engine, sometimes called a Vee engine, is a common configuration for internal combustion engines. It consists of two cylinder banks—usually with the same number of cylinders in each bank—connected to a common crankshaft. These cylinder ...

– where

, eight, ten, twelve, or even sixteen cylinders are placed in two separate planes, looking like a "V" when viewed from the end of the crankshaft. * Flat or boxer engine –where

or more cylinders are arranged in two diametrically horizontally opposed planes. *

W engine A W engine is a type of piston engine where three or four cylinder banks use the same crankshaft, resembling the letter W when viewed from the front. W engines with three banks of cylinders are also called "broad arrow" engines, due to their shap ...

– where two (narrow angle) vee engines are siamesed together (within 180°), where at eight, twelve or sixteen cylinders are arranged in four separate planes.

References

{{reflist, colwidth=50em, refs= {{cite book , last1=Pickerill , first1=Ken , editor1-last=Main , editor1-first=Larry , title=Automotive Engine Performance , edition=5th , series=Today's Technician , date=Jun 26, 2009 , publisher=Cengage Learning , location=Clifton Park, NY USA , isbn=978-1-43544-520-8 , page=464 , chapter=Glossary , quote=Longitudinal engine mounting An engine mounted lengthways in the chassis. {{cite book , first1=James E. , last1=Duffy , first2=Robert , last2=Scharff , editor1-last= Clark , editor1-first=Sandy , title=Auto Body Repair Technology , edition=4th , date=Mar 1, 2003 , orig-year=1988 , publisher=Cengage Learning , location=Clifton Park, NY USA , isbn=0-7668-6272-0 , pages=25–26 , chapter=Chapter 2: Vehicle Construction Technology , quote=A longitudinal engine mounts the crankshaft centerline front to rear when viewed from the top. Engine technology Automotive technologies