In automotive design, a FR, or front-engine, rear-wheel-drive layout is one where the

engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...

is located at the front of the vehicle and driven wheels are located at the rear via a

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 and torque and rotation, usually used to conne ...

. This was the traditional automobile layout for most of the 20th century. Modern designs commonly use the

front-engine, front-wheel-drive layout In automotive design, a front-engine, front-wheel-drive (FWD) layout, or FF layout, places both the internal combustion engine and driven roadwheels at the front of the vehicle. Usage implications Historically, this designation was used re ...

(FF). It is also used in high-floor

buses A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for char ...

and school buses.

Front mid-engine, rear-wheel-drive layout

In automotive design, a front mid-engine, rear-wheel-drive layout (FMR) is one that places the

in the front, with the rear wheels of vehicle being driven. In contrast to the front-engine, rear-wheel-drive layout (FR), the engine is pushed back far enough that its

center of mass In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force may ...

is to the rear of the front axle. This aids in

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 ...

and reduces the

moment of inertia The moment of inertia, otherwise known as the mass moment of inertia, angular mass, second moment of mass, or most accurately, rotational inertia, of a rigid body is a quantity that determines the torque needed for a desired angular accele ...

, improving the vehicle's handling. The mechanical layout of an FMR is substantially the same as an FR car. Some models of the same vehicle can be classified as either FR or FMR depending on the length of the installed engine (e.g. 4-cylinder vs. 6-cylinder) and its centre of mass in relation to the front axle.

Characteristics

* FMR cars are often characterized by a long hood and front wheels that are pushed forward to the corners of the vehicle, close to the front bumper. Grand tourers often have FMR layouts, as a rear engine would not leave much space for the rear seats. * FMR should also not be confused with a "front midships" location of the engine, referring to the engine being located fully behind the front axle centerline, in which case a car meeting the above FMR center of mass definition could be classified as a

FR layout In automotive design, a FR, or front-engine, rear-wheel-drive layout is one where the engine is located at the front of the vehicle and driven wheels are located at the rear via a drive shaft. This was the traditional automobile layout for mos ...

instead. The V35 Nissan Skyline /

Infiniti G35 The Infiniti G Line is a series of compact executive cars produced by Infiniti, a luxury division of Nissan, for the 1991–1996 and 1999–2016 model years. The first two generations of the Infiniti G (P10 and P11) were sedans based on the ...

/ Nissan 350Z are FR cars. * FMR layout came standard in most pre–World War II, front-engine / rear-wheel-drive cars. File:GMLT5.JPG, All Chevrolet Corvette from the second generation (model year 1963) through the seventh generation (model year 2019) are FMR layouts as seen in the engine bay of the Chevrolet Corvette ZR-1. File:Honda F22C Engine.JPG, The Honda S2000 engine sits clearly behind the top of the shock towers. File:Morgan 4 4 - Flickr - Alexandre Prévot (1).jpg, The

Morgan +4 The Morgan Plus 4 (or +4) is an automobile produced by the Morgan Motor Company. It is a more powerful and, in the case of the earlier cars, a slightly longer version of the company's previous 4/4 model. Plus 4 production ran from 1950 to 19 ...

and 4/4 are classic "front mid-engine, rear-wheel-drive layouts". File:Mercedes-Benz SLR McLaren engine.jpg, The engine bay of the

Mercedes-Benz SLR McLaren The Mercedes-Benz SLR McLaren (C199 / R199 / Z199) is a grand tourer jointly developed by German automotive manufacturer Mercedes-Benz and British automobile manufacturer McLaren Automotive and sold from 2003 to 2009. When the car was develope ...

. File:2006 Maserati Quattroporte - Flickr - The Car Spy (4).jpg, The 4.2-litre V8 in the Maserati Quattroporte V has FMR layout. File:Dodge Viper Motorraum.JPG, Dodge Viper showing its 8.4l V10 positioned behind the car’s front axle

References

{{DEFAULTSORT:Front-Engine, Rear-Wheel Drive Layout Car layouts

Front mid-engine, rear-wheel-drive layout

Characteristics

See also

References