automotive engineering Automotive engineering, along with aerospace engineering and naval architecture, is a branch of vehicle engineering, incorporating elements of Mechanical engineering, mechanical, Electrical engineering, electrical, Electronic engineering, electro ...

, 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 comb ...

in which the

crankshaft A crankshaft is a mechanical component used in a reciprocating engine, piston engine to convert the reciprocating motion into rotational motion. The crankshaft is a rotating Shaft (mechanical engineering), shaft containing one or more crankpins, ...

is oriented along the long axis of the

vehicle A vehicle () is a machine designed for self-propulsion, usually to transport people, cargo, or both. The term "vehicle" typically refers to land vehicles such as human-powered land vehicle, human-powered vehicles (e.g. bicycles, tricycles, velo ...

, from front to back. See also:

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 arrangement. Most rear-wheel drive vehicles use a longitudinal ...

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. A subsidiary of the Volkswagen Group, Audi produces vehicles in nine production facilities worldwide. The origins of the compa ...

, SAAB, the Oldsmobile Toronado, and the 1967 Cadillac Eldorado equipped with longitudinal engines in front wheel drive. In front-wheel drive cars a

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 the 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 the longitudinal engine orientation in combination with rear wheel drive, 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. By contrast most mainstream modern vehicles use front wheel drive along with a transverse engine arrangement since they are usually equipped with inline-4 or V6 engines. While both layouts can be adapted for

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. Types The most common forms of all-wheel drive are: ;1x1 : All unicycles Reflects one axle with ...

, the longitudinal engine orientation has a more balanced weight distribution leading to superior handling characteristics, but is less efficient in terms of packaging and interior space. 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 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, 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 Toyota Corolla, Corolla and the Toyota Starlet, Starlet. Manufactured at the Takaoka plant in Toyota City ...

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, three, four, five, six, 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 two, four, six, 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 two, four, six 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 share 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 thei ...

– 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