Both understeer and oversteer are conditions which describe your vehicle’s steering sensitivity.
They occur more commonly in racing. And less so in street driving.
But understeer and oversteer can also result from harsh driving conditions, or your driving style and driving ability.
UNDERSTEER
Understeer occurs when your vehicle turns less than you commanded with the steering wheel. It’s a common problem in front-wheel drive and all-wheel drive vehicles.
This is caused when the front tire drift is greater than the rear tire drift. To diagnose this problem, make a continuous turn by holding the wheel and throttle steady.
If your car ends up making a widening circle, you have understeer.
What do I do when I understeer?
You will probably understeer if you’re carrying too much speed into a corner.
And this will inhibit your vehicle from responding to your steering. It will turn less than you want it to.
If you find yourself in this situation, simply remove whatever factor is causing the skid.
Release the accelerator and lower your speed. Straighten the wheel and allow your front tires to gain back the needed traction.
How can I correct understeer?
• Raise the front tire pressure or lower the rear tire pressure
• Soften the front shocks or stiffen the rear shocks
• Soften the front springs or stiffen the rear springs
• Lower the front end or raise the rear end
• Install wider front tires or narrower rear tires
• Soften the front sway bar or stiffen the rear sway bar
• Increase the front negative camber
• Increase the positive caster
OVERSTEER
Oversteer occurs when your vehicle turns more than what you command it to with the steering wheel. And it’s most common in rear-wheel drive vehicles.
The main cause of oversteer is the lack of traction in your rear tires. And when there’s less traction, the drift in the rear becomes greater than it is in the front. This prominent rear drift makes your car spin inward.
What do I do when I oversteer?
You’re probably driving a rear-wheel drive car. And you’ve probably entered the turn too quickly and your rear tires are slipping.
If you use too much power at a sharper steering angle, the resulting momentum will spin your rear around.
To counter this, steer your wheel in the direction of your skid. So if you’re turning right and your rear slides left, steer to the left.
How can I correct oversteer?
• Lower the front tire pressure or raise the rear tire pressure
• Stiffen the front shocks or soften the rear shocks
• Stiffen the front springs or soften the rear springs
• Raise the front end or lower the rear end
• Install narrower front tires or wider rear tires
• Stiffen the front sway bar or soften the rear sway bar
• Reduce the front negative camber
• Reduce the positive caster
With modern stability control systems, you don’t have to worry so much about under- or oversteering. But even the most advanced electronics can’t help you counter the laws of physics. So the best way of avoiding problems is to drive within your limits.
