From Hemmings
In this day and age of electronic traction and stability control-equipped cars and trucks, terms like “oversteer” and “understeer” are heard more and more infrequently. Drivers who came of age in the era before electro-nannies, however, have very likely experienced both (particularly those living where winter is a fact of life), even if the terms themselves are unfamiliar.
Simply stated, oversteer occurs when the rear tires break traction in a corner before the front tires do, while understeer occurs when the front tires lose grip in a turn before the rears. Though this late-1980s video, found on YouTube, is aimed at teaching drivers the secret of lower autocross times, it serves up plenty of relevant advice for those driving a car built before the proliferation of computed-aided driving.
When a car begins to understeer, it takes an arc “less than desired” through the corner. This may be caused by turning in too sharply, breaking too heavily or even carrying too much speed into a turn. As instructor Dick Turner advises, the key to countering understeer is to do less of whatever it is you’re doing; if you’re on the throttle, back off a bit. If you’re on the brakes, ease up your braking effort, and if you’ve turned in too sharply, dial in a bit less steering, then lightly apply the brakes. By asking the front tires to do less work, you give them a chance to regain grip.
In understeer oversteer, the car takes an arc “greater than desired,” and the classic advice of “steer into the skid” still holds true. As Turner advises, though, it’s important to “only move your hands as fast as the car is sliding sideways.” Too much correction will generally stop a slide in one direction, only to create a slide in the opposite direction. Too little correction, and the car will continue to spin until the tires regain traction or the car hits something solid. As the old racing adage goes, oversteer is better because you don’t see what you’re about to hit.
While modern stability control systems have made driving safer for those without advanced training, even the best electronics can’t counter the laws of physics. Regardless of the vehicle, the best way to avoid oversteer or understeer is to drive within one’s limits, in a manner appropriate to conditions. That’s advice that’s relevant to everyone.