Explained: Oversteer vs Understeer

We explain the difference between oversteer and understeer, what to do when they happen, and how to avoid them in the first place.

Unintended Consequences

Jeep 4x4 in snow - media.stellantisnorthamerica.com

Like many of us, perhaps, you’ve heard the terms oversteer or understeer applied in racing or in sports car reviews, but what they are and the difference between them have thus far remained abstract. We’ll breakdown each in detail but suffice to say both oversteer and understeer occur when the car you’re driving fails to follow it’s intended path around a corner. If the car goes wide of its intended path, you’ve got understeer. If the car turns in more tightly than intended, you’ve got oversteer.

While understeer is more common in front-wheel drive cars and oversteer more common in rear-wheel drive ones, both can occur regardless of the drivetrain set up, given the right conditions. Because they come down to a loss of traction, factors like rain, snow, or ice on the road surface, cornering at excessive speeds, and balding, worn-out tires can all be contributing factors to oversteer and understeer.

What is Understeer?

Understeering - Car Throttle on youtube.com

Understeer occurs while cornering when the front wheels experience a loss of traction, the car fails to turn as tightly as intended, and instead continues to move (more or less) straight ahead. Going too fast into a turn or braking too aggressively can both initiate understeer. As we mentioned above, understeer is more common in front-wheel drive cars like the Honda Civic Type R or Volkswagen GTI. This is because the front wheels are both steering and powering the vehicle which puts greater force on the front tires; too much, and that force can exceed the traction of the tires, taking you wide of your target.

When you find yourself in an understeer situation, the best advice is to gently reduce your throttle and avoid locking the steering. It’s also important to not stomp on the brakes or just lift off the gas pedal completely. This can initiate what’s called lift-off oversteer, in which case the weigh of the car is transferred forward reducing traction at the rear wheels and causing the rear end to kick out.

Most modern cars are designed with a slight bias for understeer. It’s considered safer for a vehicle to understeer rather than oversteer since, in a collision, the front crumple zones would still be in front of passengers.

What Is Oversteer?

Oversteering - Car Throttle on youtube.com

Oversteer happens when the rear wheels lose traction in a corner and the rear end kicks out in front of the front tires, effectively taking the car on a path tighter than intended. Again, taking a corner too fast is frequently the culprit. This time most commonly occurring in rear-wheel drive cars like, say, the Mazda Miata, BMW M3, or Chevy Corvette. Because sports cars tend not only to be rear-wheel drive but also carry other features like a limited-slip differential and tightly tuned rear suspensions, they not only experience more oversteer but are often actually prized for their “tail happy” natures. After all, drifting is, in effect, a controlled oversteer situation.

But if drifting like Ken Block isn’t what you’re going for (or you don’t want to, you know, crash), you can combat oversteer by turning into the direction of the skid and slowly reducing throttle. This should allow the rear wheels to realign with the front wheels. Depending on the road conditions, such a correction can cause a counter slide i.e. fishtailing. If that happens, the same rules apply as before, turning into skid, reducing throttle, and allow the back end to realign with the front.

A Little Fun, A Little Scary

Generally, modern safety equipment like traction control and stability control can largely mitigate understeer and oversteer. However, if road conditions are reducing traction and you’re making a turn at too fast, your chances of understeer over oversteer are greatly increased. Inexperience drivers of performance cars need also be wary of the back end sliding out from behind them. By that same token, if you do master a car’s oversteer characteristics, you’ll be risking a full-blown drift mode automotive obsession. You’ve been warned.