Understeer

Understeer is a handling condition in motorsport where a car doesn't turn as sharply as the driver intends, causing the vehicle to push wide and continue in a straighter line through a corner despite steering input.

When a car understeers, the front tires lose grip before the rear tires during cornering. This means that even though you're turning the steering wheel, the car keeps going more straight than you want it to. Drivers often describe this feeling as the car "pushing" or "plowing" through a turn, as if the front end refuses to follow the desired racing line.

Imagine driving into a corner and turning the wheel to the right, but your car keeps drifting toward the outside edge of the track instead of hugging the inside line. You might turn the wheel even more, but the car still won't respond properly. That's understeer in action, and it's one of the most common handling issues in racing.

Several factors can cause understeer. The most common is simply entering a corner too fast—when you carry too much speed, the front tires can't generate enough grip to turn the car. Braking hard while turning can also cause the front wheels to lose traction. In terms of car setup, having too much weight over the front wheels, running stiff front suspension, or having worn front tires all contribute to this pushing sensation.

Front-wheel-drive cars are particularly prone to understeer because their front tires must handle both steering and putting power to the ground. When you accelerate hard while turning in these cars, the front tires become overloaded and can't do both jobs effectively, resulting in that straight-ahead push.

The effects of understeer are significant in racing. When your car won't turn properly, you're forced to slow down more than necessary to make it through corners. This costs valuable time on every lap. The constant scrubbing of the front tires as they slide also increases tire wear and can lead to overheating, further reducing grip as the race continues.

Drivers have several techniques to manage understeer when it happens. The most immediate response is to reduce throttle, which transfers weight forward onto the front tires and can help them regain grip. Advanced drivers use a technique called trail braking—continuing to brake lightly while turning in—to keep weight on the front and maintain front-end grip through the corner entry.

While understeer is generally undesirable in racing, a small amount is often built into road cars because it's considered safer for everyday drivers. A car that pushes wide is more predictable and easier to control than one that spins. However, race car drivers typically prefer a neutral balance or even slight oversteer, which allows them to rotate the car more effectively and carry higher speeds through corners.