FR layout
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In Automobile design, an FR, or Front-engine, Rear wheel drive, layout places the engine in the front of the vehicle and drive wheels at the rear. This was the traditional automobile layout for most of the 20th century. This layout is typically chosen for its simple design and weight distribution. Placing the engine at the front gives the vehicle a traditional long hood (in British English "bonnet"). Placing the drive wheels at the rear allows ample room for the transmission in the center of the vehicle.
The first FR car was an 1895 Panhard model, so this layout was known as the "Systeme Panhard" in the early years. Most cars used the FR layout until the 1980s, exemplified by the Ford Mustang, Chevrolet Corvette, and vehicles from BMW and Mercedes-Benz. The Oil crisis of the 1970s and the success of small FF cars like the Mini and Honda Civic led to the widespread adoption of that layout.
Some manufacturers, such as Volvo, retained this layout but moved the gearbox from behind the engine to between the rear wheels, putting more weight over the driven axle. This configuration is often referred to as a transaxle since the transmission and axle are one unit.
Right after the Arab Oil Embargo of 1973 and the 1979 fuel crises, a majority of American FR vehicles (station wagons, luxury sedans) were being phased out for the FF layout - this trend would spawn the SUV/van conversion market. Chrysler went 100% FF by 1990; only GM and Ford retained FR for their luxury and performance vehicles.
GM phased out its FR luxury cars after the 1996 model year, and its F-car (Chevrolet Camaro/Pontiac Firebird) in 2002; to date, no FR passenger cars are sold by GM in the United States and Canada with the exception of the 2004 Pontiac GTO (imported from Australia), Chevrolet Corvette/Cadillac XLR and the Cadillac CTS/STS.
Today, most cars are FF, though the limitations of that layout are beginning to become apparent. Many of the newest models have adopted all wheel drive, and some, like the Chrysler 300 are switching back to the FR layout. Most sports cars and luxury cars have always been FR.
Recently, a new layout called FM for Front-midships has appeared. An FM car places the engine in the front like an FR car, but pushed back enough that the engine's center of gravity is to the rear of the front axle. This aids in weight distribution and handling. Typical FM cars are high performace models such as the Nissan 350Z, Honda S2000, Ferrari 612 Scaglietti, Maserati Quattroporte, Mazda RX-7, Mazda RX-8, and the Mercedes-Benz SLR McLaren.
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