What is Understeer? And Oversteer? And Downforce?

We often hear the term used on Formula One, Top Gear etc. but what do we actually mean when we use the term Understeer, Oversteer and Downforce?Let VCARS explain.

In its most simple terms, when you’re entering a corner and the car does not turn enough and leaves the road, that’s understeer (the car is not steering enough). If the car turns too much, indeed much more sharply than you would have intended, you could get into a spin, that’s oversteer.

The terms relate to vehicle dynamics and are to the sensitivity of a vehicle to steering.

When automotive engineers define understeer and oversteer they are talking about it based on changes in the steering angle associated with changes in sideways acceleration. They measure this tendency over a sequence of circular turning tests. However, laymen and women like you and I, use the term to describe vehicle steering.


As the name might suggest, downforce is the amount of force pinning car to road. The more downforce, the more grip at higher speeds. This added grip reduces the possibility of oversteer.

Downforce can be produced by adjusting the wind flowing over the top our one’s car. The most obvious example of that is a rear spoiler on the back of one’s car. This can reduce a car’s top speed but delivers a smoother ride and more confidence when cornering.

Interestingly, when a car gets hit, it loses its grip and all of its downforce. If you’ve ever seen a Formula One car lose its rear wing, you’ll know what we mean – the resulting massive loss in downforce means they have to enter the pits and get their wings back. Now you know.


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