Have you heard the expressions, a particular car oversteers or another one understeers? Do you know exactly what is meant by each term? If you had a choice, which one would be safer to drive?
Let’s look at what is really meant by both expressions. Imagine you are in your car on a large empty parking lot, with nothing around the lot to hit, no poles or other cars.
Now you start driving and turn the wheel either right or left so that you will be driving in a circle. No problems, you are slowly driving in this big circle and everything is under control.
Now imagine that you are going a little faster, and faster around the circle. Soon you will start to hear some tire noise. As you increase your speed the sound becomes louder and the tires start to squeal. Soon they are squalling and you know that something is about to happen.
If it is becoming harder and harder to keep the front end turned in on your circle. That is, if the circle is becoming larger as you speed up, then your car understeers.
If on the other hand, the rear end of your car seems to be sliding away and seems like you will be going sideways or backwards in a second, then your car oversteers.
Oversteering cars lose the tire grip at the front of the car and understeering cars lose the tire grip at the rear of the car first.
So which one is safer? Almost all car manufactures design cars so that they understeer. This means when you drive too fast on a curve, and the front end is harder to turn you almost instinctively back off of the accelerator pedal. The car slows down and regains its grip and you go around the curve a little slower and safely.
This is fine for a typical car and average driver. But if you are in a race car, or a car designed to run on a race track, you want a car that oversteers, because you let the rear end slide out a little. This points you more into the turn and you can go faster. However, you must have the driving skills to overcome the slide while you go around the curve. Or you will slide out of control, something that’s not too bad on a race track, but can get you killed on a city street.