The term rear-wheel-drive refers to a powertrain distribution system that places rotational propulsion on the rear wheels only. Although this was the most common type of driving configuration until the end of the 20th century, today most automobiles are front-wheel drive, four-wheel drive, or all-wheel drive.
What is Rear Wheel Drive?
Rear wheel drive (RWD) means that engine power is delivered to the rear wheels which in turn push the car forward. The front wheels do not receive any power. Since the weight of an RWD vehicle is more evenly spread than many front-wheel drive vehicles, there’s a better balance of weight.
This is why most sports cars such as the Corvette and Camaro are RWD – and more exciting to drive.
Rear-wheel drive vehicles have better handling and are more rugged than most FWD cars. The RWD puts more weight to the back, balancing out the engine weight in the front. The simpler design of the RWD allows it to take obstacles more easily than the FWD.
Rear-wheel drive vehicles are better for towing because the front wheels have better steering without a ton of weight on them. Plus, with the power transfer and the tongue weight of the trailer, the rear of the vehicle squats, which gives the rear wheels more traction. If you get stuck, adding weight over the rear wheels may help.
The disadvantage of an RWD vehicle is that they do not perform well in poor weather conditions such as rain or snow because they are more prone to traction loss.
Rear-wheel drive vehicles sometimes feature 4×4. When you put the vehicle into 4×4, the vehicle will get power to all four wheels as needed.
How Does a Rear-Wheel Drive Work?
No matter its arrangement, rear-wheel drive operates in the same way. Power generated by the engine goes through the transmission to the rear wheels. The rear differential sends sufficient torque to each wheel to handle maneuvers like turns.
Most commonly, the engine and transmission will be longitudinally mounted in what is also called a north-south orientation. Engine power is delivered to the transmission input shaft, where torque multiplication takes place.
In a manual transmission vehicle, the clutch is connected to the transmission’s input shaft. On an automatic transmission, the torque converter uses an impeller and a turbine, with the turbine connected to the transmission’s input shaft.
Engine torque in low gear provides the power to begin moving the vehicle. As the vehicle gains speed, the gearing is changed so that the engine is running slower but the vehicle is moving faster.
The torque leaves the transmission output shaft by way of the propeller shaft or driveshaft, which in turn is connected to the pinion gear in the rear end. Meanwhile, the pinion gear drives a ring gear. Usually, it takes about 3 or 4 turns of the shaft-driven pinion gear for the ring gear that drives the wheels to make one full turn.
For example, a rear end with 3.20 gears may have 10 teeth on the pinion and 32 teeth on the ring gear, which multiplies the torque even further.
Inside the ring gear carrier, each axle has a gear splined to it. Between those two axle gears are some smaller pinion gears riding on a shaft that passes through the ring gear carrier.
These smaller gears are called spider gears, and they provide differential action to allow the outer wheel in a turn to spin a bit faster than the inner wheel on that same turn. This works regardless of which way the vehicle is turning. These gears don’t rotate with each other except during turns.
What Types of Cars Have Rear-Wheel Drive?
Rear-wheel drive is most commonly found in pickup trucks, performance cars, and luxury vehicles. Pickup trucks with a traditional body-on-frame construction like the Ford F-150 and Ram 1500 come standard with RWD, and they’re usually available with 4-wheel drive.
RWD is advantageous in sports cars like the Ford Mustang and Chevrolet Corvette because it’s better for weight distribution and performance. Having the front wheels dedicated to steering and the rear wheels dedicated to accelerating creates a sportier driving experience than front-wheel drive.
Luxury vehicles like the BMW 3 Series and Mercedes-Benz C-Class commonly use RWD for largely the same reason as performance cars. Luxury automakers try to deliver engaging driving dynamics, which is best achieved with either RWD or AWD.
Advantages of Rear-Wheel Drive
- RWD spreads the weight of its drivetrain more evenly than FWD from the front to the rear of the vehicle.
- Sturdy and solid- RWD can typically take a lot of abuse without expensive repairs.
- RWD drive vehicles are fast! High horsepower. High speed.
- Better stopping due to better weight distribution.
- You won’t experience “torque steer,” the tendency that FWD vehicles have to veer to the right or left during acceleration.
- Towing large loads is easier since the wheels doing the pulling are located closer to the load. Also, steering is much easier since the back wheels are providing the power while the front wheels do the work of steering.
- While drifting is not recommended for most drivers, it is easier to drift with RWD than FWD or 4WD/AWD.
Disadvantages of Rear-Wheel Drive
Reduced traction is a disadvantage of rear-wheel drive vehicles, especially in areas that get a lot of rain or snow. It is harder for the driver to control a rear-wheel drive vehicle in these conditions. The decreased traction also makes it difficult to climb steep grades or maneuver on muddy or poorly maintained roads.
Because rear-wheel drive systems are more complicated, they also cost more to manufacture. This translates to a higher sticker price for the buyer.
The rear-wheel drive may be more fun to drive, but it also makes it more difficult to master. With modern stability and traction controls, however, the driving differences of RWD don’t present a problem for most drivers.
There is less interior space due to more room needed for the transmission tunnel and driveshaft.
Is An RWD Vehicle Difficult To Control?
Rear drivers are more prone to power oversteer. Applying torque to the rear wheels while turning results in a loss of traction and causes the vehicle’s back end to step out. This isn’t necessarily a bad thing and falls into the pros column for many driving enthusiasts.
Modern stability- and traction-control systems can also intervene to make driving an RWD vehicle a nonevent, even in less-than-ideal conditions. Plus, the rear-drive enables drifting, which you should experience only on a closed course.
There’s a misconception that rear-drive vehicles are inherently worse in slick or snowy conditions, as an FWD car “pulls” itself through snow whereas an RWD car “pushes” through it.
There’s some truth to this. But with common sense, a good set of winter tires, and electronic driver aids, there’s a good chance a rear-drive car will be safe and controllable in winter conditions.
