LINGO: Understeer and Oversteer
When a car doesn't drive exactly where you've told it to on the steering wheel, that's called either understeer or oversteer depending on what the car is doing. And I don't mean you can blame your shoddy driving on your car. Usually, when understeer or oversteer occurs, it is the driver's fault, becuase you've reached the limits of what the car's handling ability can achieve. Allow me to explain:
UNDERSTEER
We call it understeer when the car doesn't turn sharply enough into the corner. In other words, it doesn't steer as much as you want it to. This phenomenon is usually associated with front wheel drive cars (power from the engine going to only the front two wheels), but it can happen with all types of cars. The reason for understeer is the loss of traction or grip on the front two wheels, and this is more common in front wheel drive cars because the front end of the car is usually heavier. Basically, if you're understeering, it's because the car isn't capable of sustaining the current speed through a corner. So if you don't want to understeer, don't take corners too fast, basically. But sometimes understeer can occur when the road surface is very slippery, like during rain, in an oil slick, or something like that.
OVERSTEER
Oversteer then, is the complete opposite of understeer - when a car turns in too sharply into a corner. It steers more than you wanted it to. Oversteer is a trait grouped with rear wheel drive cars, because oversteer occurs when there is loss of traction or grip in the rear wheels. Starting to get it now? To some, oversteer is highly desirable, because providing it is controled (ie "countersteering" by turning the wheel in the opposite direction to balance the car), it can look cool, and result in a drift. But to average people like you or me, oversteer means that we could end up facing the wrong direction. So again, slippery surfaces can cause it, and excessive speed into a corner can cause it.
Either way, if you oversteer or understeer on the road, you're probably a bit of a danger to other road users and need to reassess the way you drive. Remember to be smooth around corners, because you shouldn't need to put your foot on either the accelerator or the brakes midway through a corner.
