Drive wheel

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.[1][2]

A two-wheel drive vehicle has two driven wheels, typically both at the front or back, while a four-wheel drive has four.

A steering wheel is a wheel that turns to change the direction of a vehicle. A trailer wheel is one that is neither a drive wheel, nor a steer wheel. Front-wheel drive vehicles typically have the rear wheels as trailer wheels.

The rear driven wheels of a racing car throwing gravel

Differentials and drive shafts deliver torque to the front and rear wheels of a four-wheel drive truck

Drive wheel configurations

Front-wheel drive

Front-wheel drive (FWD) vehicles’ engines drive the front wheels. Using the front wheels for delivery of power as well as steering allows the driving force to act in the same direction as the wheel is pointing.[3] This layout is commonly used in modern passenger cars.

Opperman Motocart

A rare example of front wheel drive was the Opperman Motocart. This slow-speed agricultural and light freight vehicle was a tricycle with the front wheel carrying a large tractor tyre. The wheel was powered by a small single cylinder Douglas engine carried on the front mono fork that formed the steering gear.

Rear-wheel drive

Rear-wheel drive (RWD) typically places the engine in the front of the vehicle, with a driveshaft running the length of the vehicle to the differential transmission. However, mid engine and rear engine layouts can also used.

It was a common layout used in automobiles throughout the 20th century. At this time, FWD designs were not practical due to complexity (in FWD, engine power and steering must both be combined in the front axle).

Rear-wheel Two-wheel Four-wheel Six-wheel Eight-wheel Twelve-wheel

Two-wheel drive

For four-wheeled vehicles, two-wheel drive describes vehicles that transmit torque to at most two road wheels, referred to as either front- or rear-wheel drive. The term 4×2 is also used, to indicate four total road-wheels with two being driven.

For vehicles that have partial four-wheel drive, the term two-wheel drive refers to the mode when four-wheel drive is deactivated and torque is applied to only two wheels.

All-wheel drive

Four-wheel drive

This configuration allows all four road wheels to receive torque from the power plant simultaneously. It is often used in rally racing on mostly paved roads.

Four-wheel drive is common in off-road vehicles because powering all four wheels provides better control on loose and slippery surfaces. Four-wheel drive manufacturers have different systems such as “High Range 4WD” and “Low Range 4WD”. These systems may provide added features such as a varying of torque distribution between axles or varying gear ratios.[4]

Common terms for this configuration include four-wheel drive, 4WD, 4×4 (pronounced “four-by-four”), and all-wheel drive (AWD).

Six-wheel drive

Eight-wheel drive

Twelve-wheel drive


  1. “Driving wheel”. Retrieved 13 July 2013any wheel of a vehicle that transforms torque into a tractive force.
  2. Russ, Carey. “Driving Wheels: Introduction and Rear-Wheel Drive”. The Auto Channel. Retrieved 13 July 2013.
  3. Hillier, V.A.W.; Coombes, Peter (2004). Hilliers Fundamentals of Motor Vehicle Technology (Fifth ed.). Nelson Thornes. p. 263. ISBN 9780748780822. Retrieved 13 June2013.
  4. “”. Retrieved 2016-07-25.
Suspension A clutch is a mechanical device which engages and disengages power transmission especially from driving shaft to driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). In these devices, one shaft is typically attached to an engine or other power unit (the driving member) while the other shaft (the driven member) provides output power for work. While typically the motions involved are rotary, linear clutches are also possible. In a torque-controlled drill, for instance, one shaft is driven by a motor and the other drives a drill chuck. The clutch connects the two shafts so they may be locked together and spin at the same speed (engaged), locked together but spinning at different speeds (slipping), or unlocked and spinning at different speeds (disengaged).   Single dry-clutch friction disc. The splined hub is attached to the disc with springs to damp chatter. Friction clutches ...
Transmission brake A transmission brake or driveline parking brake is an inboard vehicle brake that is applied to the drivetrain rather than to the wheels. Historically, some early cars used transmission brakes as the normal driving brake and often had wheel brakes on only one axle, if that. In current vehicles, these brakes are now rare. They are found in some makes, notably Land Rover, usually for light off-road vehicles. Simple transmission brakes could be found in large vehicles too, such as the 16 inch single disc parking brake used in the M19 Tank Transporter of World War II. The transmission brake is provided solely as a parking brake or handbrake. Normal wheel brakes are still provided for use when driving, drum brakes originally, now almost always disc brakes. Driver's manuals usually caution against using the transmission brake when driving, as it is neither powerful enough nor robust enough and so will not work effectively and may even be damaged by trying to stop a moving vehicle. ...
Differential (mechanical device) A differential is a gear train with three shafts that has the property that the rotational speed of one shaft is the average of the speeds of the others, or a fixed multiple of that average. A spur gear differential constructed by engaging the planet gears of two co-axial epicyclic gear trains. The casing is the carrier for this planetary gear train. Overview Automotive differential: The drive gear 2 is mounted on the carrier 5 which supports the planetary bevel gears 4 which engage the driven bevel gears 3 attached to the axles 1. ZF Differential. The drive shaft enters from the front and the driven axles run left and right. Car differential of a Škoda 422 In automobiles and other wheeled vehicles, the differential allows the outer drive wheel to rotate faster than the inner drive wheel during a turn. This is necessary when the vehicle turns, making the wheel that is traveling around the outside of the turning c...
Torque converter A torque converter is a type of fluid coupling which transfers rotating power from a prime mover, like an internal combustion engine, to a rotating driven load. In a vehicle with an automatic transmission, the torque converter connects the power source to the load. It is usually located between the engine's flexplate and the transmission. The equivalent location in a manual transmission would be the mechanical clutch. The key characteristic of a torque converter is its ability to multiply torque when the output rotational speed is so low that it allows the fluid coming off the curved vanes of the turbine to be deflected off the stator while it is locked against its one-way clutch, thus providing the equivalent of a reduction gear. This is a feature beyond that of the simple fluid coupling, which can match rotational speed but does not multiply torque, thus reduces power. Some of these devices are also equipped with a "lockup" mechanism which rigidly binds the engine to th...
Non-synchronous transmission A non-synchronous transmission is a form of transmission based on gears that do not use synchronizing mechanisms. They are found primarily in various types of agricultural and commercial vehicles. Because the gear boxes are engineered without "cone and collar" synchronizing technology, the non-synchronous transmission type requires an understanding of gear range, torque, engine power, range selector, multi-functional clutch, and shifter functions. Engineered to pull tremendous loads, often equal to or exceeding 40 tons, some vehicles may also use a combination of transmissions for different mechanisms. An example would be a power take-off. History In 1890, Panhard used a chain-drive with a Daimler engine in a horseless carriage. Industrial marketing has since then coined spectacular names for various vehicle parts. Changing from the Locomobile, a 1906 race-car to what is now called the automobile, advertisers used design wording from the engineering departments to give new ideas a de...