Benefits of Rear Wheel Drive Cars

The biggest benefit to rear wheel drive is that it spreads the loads of the car across all four tires of a car. In a rear wheel drive car the rear wheels do the pushing while the front wheels are reserved for the steering duties. In front wheel drive cars the front tires must perform both functions. Each front tire in a front wheel drive car must do two tasks. Both the cornering forces and the engine acceleration/deceleration forces in a front drive car act on the same tire.

So in a front drive the tires capacity can be easily exceeded. In a rear drive car the rear tires handle the engine acceleration/deceleration while the front only need to handle the steering forces. Not only does this balance the load on the tires but it reserves the front tires exclusively for the all important steering duties.

Other Benefits to Rear Wheel Drive.

O.K., some assumptions : All comparisons are of equal weight cars without traction control. Braking comparisons assume maximizing the ability (two feet on the pedal pressing as hard as possible) of a perfectly working four channel anti-lock brake system.

  • Better weight balance.Most rear wheel drive cars have the engine in the front and the drive components in the rear. Front drive cars have everything up front. By properly balancing the front and rear of the car you can improve the handling, acceleration, braking, and thus safety of a car.
  • Better acceleration.On all but the slipperiest surfaces rear wheel drive cars accelerate faster than a front drive car from a stop. This is because when you accelerate quickly from a stop the weight of the car transfers to the rear of the car. In a rear drive car this places extra weight on the rear of the car, essentially jamming the tires into the road greatly increasing traction. In a front drive car, when the weight goes to the rear, weight is taken off of the front wheels. This allows the front wheels lose traction and spin easier. If the wheels are spinning not only does this slow you down but it also makes it difficult to steer the car. In the rear drive car the front tires are available for steering even if the rears have lost traction.
  • Better Road Holding.The better weight balance of rear wheel drive allows the car to handle better. The more even weight allows the car to drive neutrally through a corner. This means both the front and rear of the car have near equal loads acting upon them. In a front drive car the the heavy front end causes the front end to have a higher load on it. This will cause the front tires to eventually lose grip well before the rear tires are fully loaded. Front tires on front drive cars do much more work than the rears causing them to wear out much faster. It is best to balance the load as best you can among the four tires. If you are accelerating or slowing down (engine braking) these forces will act upon the already heavily loaded front tires of a front drive car. In a rear drive car the front tires are left for steering even when accelerating or engine braking. Sharing the work among all four tires is the key.
  • Better Stopping.Because of the better balance rear drive cars brake better. When you stop a front drive car the excess weight in the front of the car allows the force on the front tires to exceed the limits of the tires. The relatively low weight on the rear of a front drive car does not allow the tires to be used to their maximum ability. When panic stopping weight will transfer to the front in both rear and front drive cars but there is more weight left for rear braking action in the rear drive car.
  • No Torque Steer.Front wheel Drive cars have a problem known as Torque Steer. This occurs when the acceleration of the engine effects the cars steering. Since the driveline is connected to the steering wheels the torque of the engine applies force to the front wheels causing the car to pull to the right during acceleration. Rear Drive cars do not have this problem since the engine is not connected to the steering gear.
  • Better Ride and Feel.The light front end of the car allows it to "turn in" to a corner easier. The car feels more nimble and controllable. Since the front is not so heavy it is not burdened by needing strong springs to keep it under control. This allows the suspension to be set up softer while maintaining good control ability. The absence of drive shafts (half shafts) and CV joints in the front of the car allows the front suspension to be designed for maximum steering efficiency. The lower rotating weight of the front wheel assemblies improves steering response and ultimate grip. Granted that a rear drive car has more weight at the rear but it can be handled by the underutilized (compared to the front tires in a front driver) rear tires.
  • Better Serviceability / More Rugged.Ever notice that cops and taxis avoid front wheel drive like the plague? That is because rear wheel drive cars are more rugged and easier and cheaper to fix.
  • Better Ultimate Ability.. Purpose built race cars are almost always rear wheel drive. In production based racing series front wheel drive cars are given a performance advantage to make them equal to rear drive cars. Usually this is in the form of a weight break. Granted we shouldn't be driving our cars like race cars on the street but in an emergency having the extra ability in the car is an advantage I would like to have.

So why do automakers use front drive cars?

Well I guess there are a couple of good reasons I can think of. Anybody else have any more? If so e-mail me and let me know.

  • Traction in Snow and Ice.When not under hard acceleration front drive cars have more weight over the front wheels. This gives more traction for acceleration in very slippery conditions. This is the biggest perceived advantage to a front drive car. However, today's rear wheel drive cars with traction control and independent suspension do very good in the snow. But for areas of the country that have extreme amounts of winter weather this may be enough to justify a front wheel drive car.
  • Packaging.In front drive cars the engine and drivetrain can be pre-assembled as one unit and then popped in to the car during assembly. This probably leads to a more efficient assembly operation.
  • Cost.Due to easier manufacturing and a few less components it may be cheaper to manufacture a FWD car.
  • Passenger/Trunk Space.Since you do not need to run a driveshaft down the middle of the car you may be able to get more interior room. Funny that front drive cars have a hump down the middle anyway! Not having a rear drive suspension can allow the trunk area to be larger.
  • Demand.Until we tell the automakers we want rear drive cars they won't build them. So let's tell them!