A rear-engine, front-wheel-drive layout is one in which the engine is between or behind the rear wheels, and drives the front wheels via a driveshaft, the complete reverse of a conventional front-engine, rear-wheel-drive vehicle layout.
The earliest example of the form appeared in 1932, with the design and construction of the prototype Maroon Car by chief designer Harleigh Holmes at Coleman Motors, an established builder of Front- and All-Wheel-Drive vehicles based in Littleton, Colorado. [1] The car had front-wheel drive and was powered by a rear-mounted V-8 engine. Only one was built and the vehicle was never placed in production. [2]
Since then, it has remained an extremely uncommon drive layout throughout automotive history, used only by a few prototypes and concept cars, such as Buckminster Fuller's 1933 Dymaxion car, which was able to turn within its wheelbase thanks to rear-wheel steering, [3] and the 1947 Gregory Sedan, [4] an early ponton-style prototype for a 5-seat subcompact car, [6] now held at the Lane Motor Museum. [7]
The layout has occasionally seen renewed interest as a potential option for innovative car designs, such as in the 1999 patent application of inventor–engineer Michael Basnett at the former Rover Group, which proposed a front transaxle, rear quasi-flat engine (an inline-4, turned 90 degrees) architecture, with the fuel tank placed where the right-hand cylinder bank would have been in a "true" flat engine; overall somewhat mimicking the "pancake engine" design of the Volkswagen Type 3 but in water-cooled form and without rear drive.
According to the patent, the layout is designed to be advantageous in terms of crash performance by increasing the front crumple zone, in allowing greater styling freedom, in enhanced ride via reduced noise, vibration, and harshness, and in lowered center of gravity providing improved handling, braking and roll characteristics—as well as, much like the Type 3, increased cabin and cargo space within the same chassis footprint and body height. Its main disadvantage is the lack of weight over the drive wheels, particularly under hard acceleration as weight shifts to the rear.
However, as mentioned in a Jalopnik article listing all known RF-layout cars, [8] it too appears to have been nothing more than a speculative exercise, without so much as a single physical prototype being built—and the point of whether Rover Group intended to develop it any further is moot, as the corporation was broken up and its assets sold off barely a year later, with the fate of that particular piece of IP being unclear.
The drivetrain design closest to RF in actual series production vehicles is the mid-engine, four-wheel-drive layout, typically seen in high end sportscar designs, and which, with the use of power-split centre differentials or hybrid drive systems, can be set up to send a variable amount of the total drive to the front wheels, in some cases up to 100%. Electric front-wheel-drive vehicles can also be found with small range-extender motor-generators, which are typically mounted in the rear luggage compartment, but do not technically count as RF drivetrain as there is no direct mechanical link between engine and wheels, or even the generated engine power and drive motor output, as the generator tends to run at a constant speed and is used to maintain battery charge rather than power the motor directly.
The Dymaxion car was designed by American inventor Buckminster Fuller during the Great Depression and featured prominently at Chicago's 1933/1934 World's Fair. Fuller built three experimental prototypes with naval architect Starling Burgess – using donated money as well as a family inheritance – to explore not an automobile per se, but the 'ground-taxiing phase' of a vehicle that might one day be designed to fly, land and drive – an "Omni-Medium Transport". Fuller associated the word Dymaxion with much of his work, a portmanteau of the words dynamic, maximum, and tension, to summarize his goal to do more with less.
Four-wheel drive, also called 4×4 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 providing an additional output drive shaft and, in many instances, additional gear ranges.
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 longitudinal engine arrangement generally found in rear-wheel drive and four-wheel drive vehicles.
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.
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 bumper. Although very common in transit buses and coaches due to the elimination of the drive shaft with low-floor buses, this layout has become increasingly rare in passenger cars.
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 drive vehicles feature a longitudinally-mounted engine at the front of the car.
A drive shaft, driveshaft, driving shaft, tailshaft, propeller shaft, or Cardan shaft is a component for transmitting mechanical power and torque and rotation, usually used to connect other components of a drivetrain that cannot be connected directly because of distance or the need to allow for relative movement between them.
The Honda Legend is a series of V6-engined executive cars/mid-size luxury sedans produced by Honda since 1985 which currently serves as its flagship vehicle. It is larger than the Honda Accord. It also provided the basis for the Acura Legend, RL and RLX — the successive flagship vehicles of Honda's luxury Acura division in North America from 1986 until 2020.
Hybrid Synergy Drive (HSD), also known as Toyota Hybrid System II, is the brand name of Toyota Motor Corporation for the hybrid car drive train technology used in vehicles with the Toyota and Lexus marques. First introduced on the Prius, the technology is an option on several other Toyota and Lexus vehicles and has been adapted for the electric drive system of the hydrogen-powered Mirai, and for a plug-in hybrid version of the Prius. Previously, Toyota also licensed its HSD technology to Nissan for use in its Nissan Altima Hybrid. Its parts supplier Aisin Seiki Co. offers similar hybrid transmissions to other car companies.
A drive wheel is a wheel of a motor vehicle that transmits force, transforming torque into tractive force from the tires to the road, causing the vehicle to move. The powertrain delivers enough torque to the wheel to overcome stationary forces, resulting in the vehicle moving forwards or backwards.
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 use a longitudinal engine configuration, where the engine's crankshaft axis is parallel with the direction of travel, except for some rear-mid engine vehicles, which use a transverse engine and transaxle mounted in the rear instead of the front. Despite typically being used in light vehicles, it is not restricted to such designs and has also been used on armoured fighting vehicles to save interior space.
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 were sedans based on the Nissan Primera. Beginning with its third generation (V35), the Infiniti G have been rebadged versions of the Nissan Skyline line of sedans and coupes that were exported to the United States and Canada. The current incarnation is the fourth generation (V36) which introduced the hardtop coupe convertible. The Nissan FM platform, on top of which the third and fourth generations of the Infiniti G have been built, also underpins the Nissan 370Z and has shared components with the Infiniti M, Infiniti EX, and Infiniti FX.
Super Handling-All Wheel Drive (SH-AWD) is a full-time, fully automatic, all-wheel drive traction and handling system, which combines front-rear torque distribution control with independently regulated torque distribution to the left and right rear wheels. This way the system freely distributes the optimum amount of torque to all four wheels according to the driving conditions." The system was announced in April 2004, and was introduced in the North American market in the second generation 2005 model year Acura RL, and in Japan as the fourth generation Honda Legend.
Hybrid vehicle drivetrains transmit power to the driving wheels for hybrid vehicles. A hybrid vehicle has multiple forms of motive power.
The powertrain layout of a motorised vehicle such as a car is often defined by the location of the engine and drive wheels.
The following outline is provided as an overview of and topical guide to automobiles:
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, and is an important part of rally racing, as well as off-road driving. In terms of racing purposes, whether it be on-road or off-road, can be described as follows,
A team that pursues the Weak LS4WD architecture will minimize the development cost of the front-wheel drive system at the expense of having a larger rear powertrain. The Weak architecture produces a vehicle with a large powersplit between the front and rear powertrains, while the Strong architecture recommends a vehicle with more similar power and torque requirements for the front and rear.
The Lohner–Porsche Mixed Hybrid was the first gasoline-electric hybrid vehicle.
The Institec Justicialista was a line of cars produced by the government of Argentina via IAME from 1954 to 1955 as an attempt to develop a native Argentine automotive industry. It used a front-engine, front-wheel-drive layout with a two-stroke two-cylinder engine derived from a German DKW design and a conventional metal body. Due to the insistence of General Juan Domingo Perón a sports car prototype was made, a two-seat version was showcase as roadster in the Paris Motor Show. The prototype was repurposed Porsche with a fiberglass body powered by a 1.5-liter air-cooled Porsche flat-four engine and a Porsche four-speed gearbox driving the front wheels.
A drivetrain 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 of a motor vehicle that deliver power to the drive wheels. This excludes the engine or motor that generates the power. In marine applications, the drive shaft will drive a propeller, thruster, or waterjet rather than a drive axle, while the actual engine might be similar to an automotive engine. Other machinery, equipment and vehicles may also use a drivetrain to deliver power from the engine(s) to the driven components.