Understeer
A vehicle handling characteristic where the front wheels lose traction first, causing the vehicle to slide straight.
Understeer is a vehicle handling dynamic that occurs when a vehicle turns less sharply than the driver's steering input commands, causing the front tires to slide and plow forward. In simple terms, it is when the vehicle wants to go straight even though the front wheels are turned.
Understeer occurs when the front tires exceed their limit of adhesion (grip) before the rear tires do. Most mass-market passenger cars are intentionally designed by manufacturers to understeer near the limit of traction because it is safer and more intuitive for average drivers to manage—simply lifting off the throttle transfer weight forward, restoring front grip. Factors like FWD layout, front-heavy weight distribution, and hard front tires promote understeer.
If a vehicle is experiencing excessive understeer during normal driving, it indicates issues like worn front shock absorbers, under-inflated front tires, or incorrect front alignment settings (such as excessive positive camber). Mechanics check tire pressure and suspension wear when diagnosing handling complaints, and may suggest stiffer rear anti-roll bars or alignment adjustments to balance handling.