In snow and sleet, rear-wheel drive cars are difficult to steer. Yet, in the press, these cars are always praised for their superior handling. Is a rear-wheel drive just as safe?

Answer

A major drawback of rear-wheel drive is oversteer. Oversteer occurs when the maximum grip of the rear tires on the road is exceeded. The car slides, as it were, over the rear tires to the outside of the bend. The effect is that the rear of the car threatens to overtake the front, which in an extreme case can result in a spin. With many cars this can happen very unexpectedly and it is sometimes difficult to estimate. Especially with a slippery road surface (rain, snow, mud, sand, leaves) this can cause problems, especially for ‘sporty’ drivers who have too little experience with rear-wheel drive cars.

Understeer is more likely to occur in a front-wheel drive vehicle. Understeer occurs when the maximum grip of the front tires on the road is exceeded. The effect is that the car makes a shallower turn than the driver would expect. The car slides, as it were, over the front wheels to the outside of the bend.

For average car users, a slight understeer is more desirable than oversteer because it is easier to control. A limited amount of understeer informs the driver in good time that he or she needs to slow down, otherwise the car will fly out of the bend. The natural response to understeer is to slow down, and this is just the necessary action that has a stabilizing effect.

Correcting oversteer can always be done by countersteering or by adjusting the throttle: the weight of the car is shifted towards the rear axle, resulting in a stabilizing effect. This is not an automatic response for inexperienced drivers. In an oversteered car, slowing down the throttle will only amplify the effect.

However, rear-wheel drive also has advantages, especially in cars with a lot of engine power. For example, the rear wheels have more traction, because during intense acceleration a larger part of the weight of the car is exerted on the rear wheels. With front-wheel drives with a lot of power, the front wheels slip quickly during a sprint. Rear-wheel drive also has a positive influence on the steering behaviour. Due to the absence of driving forces on the steering wheels, the steering remains precise, even at a slightly faster speed. This is the second reason why most sports cars have rear-wheel drive. Modern techniques such as ESP (electronic stability program) can effectively nip sudden oversteer in the bud, so that modern rear-wheel drive vehicles are certainly not dangerous vehicles.