
Oversteer occurs more commonly on cars that have rear-wheel drive systems. When the rear end of your car loses its grip, it can slide out and cause your car to fishtail. To help address oversteer, you can loosen the suspension on your car or its downforce to help the rear end grip the road easier.
Understeer, on the other hand, will happen more commonly with cars that have front-wheel drive. If you accelerate too fast while turning or turn the steering wheel too quickly, you can cause the wheels to not turn quick enough. By increasing the suspension or front wing, or even adjusting the tire pressure, you can help minimize understeering.