In automobile design, a rear-engine design layout places the engine at the rear of the vehicle. The center of gravity of the engine itself is past the rear axle. This is not to be confused with the center of gravity of the whole vehicle, as an imbalance of such proportions would make it impossible to keep the front wheels on the ground. Rear-engine position / Rear-wheel drive Rear-engined cars are almost always rear wheel drive, a layout known as RR. The exception is certain high performance four wheel drive models from some European automakers. This layout is chosen for three reasons - packaging, traction, and ease of manufacture:
- Since the engine is located at an extremity, the rest of the vehicle can be used for passengers and luggage.
- Having the engine located over the driven wheels increases downward pressure, which is helpful for grip on loose surfaces.
- The drivetrain can be assembled as a unit and installed easily at the factory - easier than a front wheel drive layout where the driven wheels also steer the car.
A rear wheel drive, rear engine car tends to be prone to oversteer which allows for tighter turner radius than that of a neutral or understeer condition of a vehicle, however this causes vehicle instability. For this reason rear engine has been abandoned as a design option regular passenger car, but still maintains viability for race applications.[1]
Although this layout was once popular, it was mainly found in small, inexpensive cars and light commercials, most car makers have abandoned the rear-engined layout apart from Porsche who has gradually developed their design with improvements to the suspension and chassis to reduce the shortcomings of the layout to exceptional levels in road and race cars.
The most popular current applicaton of this layout is in Low-floor buses where its spacesaving attributes are best applied.
On the De Lorean, to compensate for the uneven (35/65) weight distribution caused by the rear-mounted engine, the car had rear wheels with a diameter slightly greater than the front wheels.
Some rear-engined cars
Smart Fortwo's three-cylinder engine officially sits behind the rear axle.
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BMW 600 and 700
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Chevrolet Corvair
- De Lorean DMC-12
- Dune buggies such as the Meyers Manx
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FIAT 500, 600, 850, 126 and 133
- Hillman Imp
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NSU Prinz
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Porsche 356, 911 and 959
- Mercedes-Benz 130/150/170H
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Renault 4CV, Dauphine, Caravelle, R8, R10
- Renault Alpine
- Simca 1000
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koda 1000/1100MB,MBX, 100/110, 110R, 105/120/125, 130/135/136, Garde, Rapid
- Smart Fortwo
- Smart Roadster
- Tatra T77 / T87 / T97 / T603 / T613
- Tucker Torpedo
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Volkswagen Beetle, type 3 'pontoon', Karmann Ghia and type 4 (411/412), as well as the VW Bus and type 181 'Thing'
- Tata Nano
- Benz Patent motorwagen
References
de:Heckantrieb fa: id:Mesin belakang it:Motore posteriore pt:Motor traseiro
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