ASE G1 Auto Maintenance and Light RepairSuspension and SteeringEasy
A technician is performing a pre-alignment inspection on a vehicle. They notice that the tires are worn excessively on both the inner and outer shoulders, but the center of the tread is relatively unworn. Which of the following conditions is the MOST likely cause of this tire wear pattern?
- AOverinflation
- BExcessive positive camber
- CWorn steering linkages
- DUnderinflation
Show answer & explanationAnswer & explanation
Correct answer: D. Underinflation
Underinflation causes the tire to sag in the center, putting more pressure and wear on the inner and outer shoulders. The center of the tread makes less contact with the road, thus wearing less.
Why the other options are wrong
- A. Overinflation causes wear primarily in the center of the tire.
- B. Excessive positive camber causes wear on the outer shoulder of the tire.
- C. Worn steering linkages typically cause irregular wear, feathering, or wandering, not specific wear on both shoulders with an unworn center.
Tire Underinflation Wear
A tire wear pattern where both the inner and outer shoulders of the tread are excessively worn, while the center tread remains relatively unworn, due to insufficient tire pressure.
- Wear on both inner and outer shoulders.
- Center tread is less worn.
- Caused by insufficient air pressure.
Memory trick: Under-pressure, tire's 'shoulders' take the brunt, center's a runt.