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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.
The most common layout for a rear-wheel drive car is with the engine and transmission at the front of the car, mounted longitudinally.
Other layouts of rear-wheel drive cars include front-mid engine, rear-mid engine, and rear-engine.
Some manufacturers, such as Alfa Romeo, Lancia, Porsche (944, 924, 928) and Chevrolet (C5, C6, and C7 Corvettes), place the engine at the front of the car and the transmission at the rear of the car, in order to provide a more balanced weight distribution. This configuration is often referred to as a transaxle since the transmission and axle are one unit.
Many of the cars built in the 19th century were rear-wheel drive, often with the engine mounted at the rear of the car. The first rear-wheel drive car with the engine mounted at the front was an 1895 Panhard model, so this layout was known as the "Système Panhard" in the early years. The layout has the advantage of minimizing mechanical complexity, as it allows the transmission to be placed in-line with the engine output shaft, spreading weight under the vehicle. In comparison, a vehicle with the engine over the driven wheels eliminates the need for the drive shaft (replacing this with the transaxle of lighter combined weight), but has the disadvantage of concentrating all the weight in one location.
In order to reduce the relative weight of the drive shaft, the transmission was normally split into two parts: the gearbox and the final drive. The gearbox was normally produced with its highest gear being 1:1, which offers some mechanical advantages. The final drive, in the rear axle, would then reduce this to the most appropriate speed for the wheels. As power is the product of torque and angular velocity, spinning the shaft faster for any given power reduces the torque and allows a lighter shaft construction.
In an era when petrol was cheap and cars were heavy, the mechanical advantages of the front-engine, rear-wheel-drive (FR) drivetrain layout made up for any disadvantage in weight terms. It remained almost universal among car designs until the 1970s.
After the Arab oil embargo of 1973 and the 1979 fuel crises, a majority of American FR vehicles (station wagons and luxury sedans) were phased out for the front-engine, front-wheel drive (FF) layout – this trend would spawn the SUV-van conversion market. Throughout the 1980s and 1990s, most American companies set as a priority the eventual removal of rear-wheel drive from their mainstream and luxury lineup. [1] Chrysler went 100% FF by 1990 and GM's American production went entirely FF by 1997 except the Corvette, Firebird and Camaro. Ford's Mustang [2] has stayed rear-wheel drive, as it must maintain a sporty presence, as were Ford's full-size cars based on the Ford Panther platform (the Ford Crown Victoria, Mercury Grand Marquis, and Lincoln Town Car) until they were discontinued in 2011 in favour of the Ford Taurus, which Ford discontinued production in 2019, being formally available with either a transverse front-wheel drive or all-wheel drive layout. [3]
In Australia, FR cars remained popular throughout this period, with the Holden Commodore and Ford Falcon having consistently strong sales until their discontinuation in the late 2010s. In Europe, front-wheel drive was popularized by small cars like the Mini, Renault 5 and Volkswagen Golf and adopted for all mainstream cars. Upscale marques like Mercedes-Benz, BMW, and Jaguar remained mostly independent of this trend and retained a lineup mostly or entirely made up of FR cars. [4] Japanese mainstream marques such as Toyota were almost exclusively FR until the late 1970s and early 1980s. Toyota's first FF vehicle was the Toyota Tercel, with the Corolla and Celica later becoming FF while the Camry was designed as an FF from the beginning. The Supra, Cressida, Crown, and Century remained FR. Luxury division Lexus has a mostly FR lineup. Subaru's BRZ is an FR car. The fact that a driveshaft is needed to transfer power to the rear wheels means a large centre tunnel between the rear seats; therefore, cars such as the Mazda RX8 and the Porsche Panamera forgo a centre rear seat and divide both seats by a centre tunnel.
In the 21st century, most cars are FF, including all front-engined economy cars, though FR cars are making a return as an alternative to large sport-utility vehicles. In North America, GM returned to the production of FR-based luxury vehicles with the 2003 Cadillac CTS. As of 2012, all but the SRX and XTS are FR-based vehicles. Chevrolet reintroduced the FR-based Camaro in 2009, and the Caprice PPV in 2011. Pontiac also had a short run with the FR-based G8 and Pontiac Solstice. A Chevrolet replacement for the G8 called the Chevrolet SS was released in 2013 and uses the FR layout. Chrysler and Dodge reintroduced the 300 and Charger on a FR platform. They also maintain FR layout on the now unibody Grand Cherokee and Durango. Hyundai and Kia have also been working with new FR-based vehicles in the US, the Genesis Coupe and Sedan, the Equus and the new[ when? ] Kia Quoris. Ford, on the other hand, seems to be moving away from FR-based vehicles[ citation needed ] with the discontinuation of the Panther Platform in 2011 and the Australasia-only Falcon in 2016. Excluding trucks, vans, and SUVs, the Mustang is the only FR vehicle remaining in their lineup.
The Chevrolet Corvair is a rear-engined, air-cooled compact car manufactured by Chevrolet in two generations between 1960–1969. A response to the Volkswagen Beetle, it was produced in 4-door sedan, 2-door coupe, convertible, 4-door station wagon, passenger van, commercial van, and pickup truck body styles in its first generation (1960–1964), and as a 2-door coupe, convertible or 4-door hardtop in its second (1965–1969). Total production was approximately 1.8 million vehicles from 1960 until 1969.
A four-wheel drive, also called 4×4 or 4WD, is 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.
The Ford Probe is a liftback coupé produced by Ford, introduced in 1988 and produced until 1997. The Probe was the result of Ford's collaboration with its longtime Japanese partner Mazda, and both generations of Probe were derived from the front-wheel drive Mazda G platform that underpinned the Mazda Capella.
Pony car is an American car classification for affordable, compact, highly styled coupés or convertibles with a "sporty" or performance-oriented image. Common characteristics include rear-wheel drive, a long hood, a short decklid, a wide range of options to individualize each car and use of mass-produced parts shared with other models. The popularity of pony cars is largely due to the launch of the Ford Mustang in 1964.
Front-wheel drive (FWD) is a form of engine and transmission layout used in motor vehicles, in which 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.
In automotive design, an RMR, or rear mid-engine, rear-wheel-drive layout is one in which the rear wheels are driven by an engine placed with its center of gravity in front of the rear axle, and thus right behind the passenger compartment. Nowadays more frequently called 'RMR', to acknowledge that certain sporty or performance focused front-engined cars are also "mid-engined", by having the main engine mass behind the front axle, RMR layout cars were previously just called MR, or mid-engine, rear-wheel-drive layout), because the nuance between distinctly front-engined vs. front mid-engined cars often remained undiscussed.
A front-engine, rear-wheel-drive layout(FR), also called Systeme Panhard is an automotive design with an engine in front and rear-wheel-drive, connected via a drive shaft. This arrangement, with the engine straddling the front axle, was the traditional automobile layout for most of the 20th century. It is also used in trucks, pickups, and high-floor buses and school buses.
A transaxle is a single mechanical device which combines the functions of an automobile's transmission, axle, and differential into one integrated assembly. It can be produced in both manual and automatic versions.
In automotive engineering, a mid-engine layout describes the placement of an automobile engine in front of the rear-wheel axles, but behind the front axle.
The Ford Aerostar is a range of vans that was manufactured by Ford from the 1986 to the 1997 model years. The first minivan produced by Ford, the model line was marketed against the Chevrolet Astro/GMC Safari and the first two generations of the Chrysler minivans. Introduced shortly before the Ford Taurus, the Aerostar derived its name from its slope-nosed "one-box" exterior.
A drive shaft, driveshaft, driving shaft, tailshaft, propeller shaft, or Cardan shaft is a component for transmitting mechanical power, 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.
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 offers similar hybrid transmissions to other car companies.
The Hotchkiss drive is a shaft drive form of power transmission. It was the dominant means for front-engine, rear-wheel drive layout cars in the 20th century. The name comes from the French automobile manufacturer Hotchkiss, although other makers, such as Peerless, used similar systems before Hotchkiss.
A torque tube system is a power transmission and braking technology that involves a stationary housing around the drive shaft, often used in automobiles with a front engine and rear drive. The torque tube consists of a large diameter stationary housing between the transmission and rear end that fully encloses a rotating tubular steel or small-diameter solid drive shaft that transmits the power of the engine to a regular or limited-slip differential. The purpose of a torque tube is to hold the rear end in place during acceleration and braking. Otherwise, the axle housing would suffer axle wrap, which is when the front of the differential lifts excessively during acceleration and drops down during braking. Its use is not as widespread in modern automobiles as is the Hotchkiss drive, which holds the rear end in place and prevents it from flipping up or down, during acceleration and braking by anchoring the axle housings to the leaf springs using spring perches.
In automotive engineering, a longitudinal engine is an internal combustion engine in which the crankshaft is oriented along the long axis of the vehicle, from front to back. See also: transverse engine
ATTESA is a four-wheel drive system used in some automobiles produced by the Japanese automaker Nissan, including some models under its luxury marque Infiniti.
In automotive design, a front-mid-engine, front-wheel-drive layout is one in which the front road wheels are driven by an internal-combustion engine placed just behind them, in front of the passenger compartment.
The powertrain layout of a motorised vehicle such as a car is often defined by the location of the engine or motors and the drive wheels.
