What is RWD? Features and technical specifications

What is RWD? Features and technical specifications

RWD is the general term used for rear-wheel drive systems on all makes of passenger and commercial vehicles. It means that the engine torque is transferred to the rear wheels. This type of drivetrain was widely used in the 20th century. Nowadays, RWD is becoming less common. As a rule, sports cars with powerful engines, such as the Dodge Challenger and Charger, Chevrolet SS, Chrysler 300, Subaru BRZ, Hyundai Genesis Coupe, and Mazda MX-5, among others, are equipped with it.

How RWD works

In most rear-wheel-drive cars, the engine and transmission are mounted in the front. The engine torque is transferred via the propeller shaft to the rear axle final drive, and from the final drive to the wheel differential. The final drive increases the torque supplied from the engine. The differential distributes it between the drive wheels. The front axle is not coupled with the transmission.

There are other types of layout available. For instance, the engine can be mounted in the front of the car, while the transmission is then mounted in the same housing as the rear axle final drive. The propeller shaft is used to transfer the torque from the engine to the transmission. On some vehicles, the engine is mounted in the rear and housed with the transmission and the final drive in one unit.

Types and features of RWD

RWD layout Engine location Transmission location Advantages Disadvantages Cars with rear-wheel drive
Front In front of or above the axle In the front, less often in the rear
  • Excellent handling on dry surfaces.
  • Even tyre wear.
  • Increase in vehicle weight.
  • Reduced interior space.
  • Substantial power loss.
Alfa Romeo Stelvio 949, Spider 939; Cadillac CTS A1LL; Chevrolet Corvette С7; Aston Martin Vantage Volante; Audi 100 Coupé S C1 F104.
Mid Behind the axle
  • Reduced load on front axle
  • Unusual interior layout.
  • Lack of or small luggage compartment.
Mazda RX-7 FD; Dodge Viper SRT-10; Daihatsu Hijet S85, S200; BMW Z8 E52; Ferrari 599 GTB Fiorano, Portofino; Lexus LFA; Mercedes-Benz SLR McLaren R199; Lotus Seven.
Mid In front of the axle In the rear
  • Improved drive wheel traction, especially on slippery surfaces.
  • Excellent handling.
  • Ability to corner at high speed.
  • Reduced road-holding ability.
  • Engine difficult to access.
  • Small interior capacity.
  • Complicated engine cooling system design.
De Tomaso Pantera; Ford GT; Ferrari Enzo; Toyota MR2; Porsche Carrera GT 980, Boxster 987, 981, Cayman 987, 981; Jaguar XJ220 Х27.
Rear Behind the axle
  • Reduced vehicle weight.
  • Excellent dynamics.
  • Good traction and stability on slippery surfaces.
  • Low interior noise level.
  • Optimal brake force distribution.
  • Oversteer.
  • Underperformance of the steering system.
  • Reduced body stability in lateral wind.
  • Complicated design of the engine cooling system and cabin heating; difficult to repair as a result.
Renault Twingo CNO, BCM; Smart Fortwo 451, 453, City Coupe 450; Porsche 911 997; Tesla Model S 5YJS.

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