In the automotive industry, we get asked all the time "why are my tires wearing uneven"? There are several factors that can cause a tire to wear unevenly, or wear worse on the inside or outside than in the middle. The number one factor is the vehicle being out of alignment. Having you alignment checked a couple times a year can be crucial to keeping your tires wearing properly. Another factor can be lack of having your tires rotated regularly. We recommend tire rotations at least every other oil change. The engine of a vehicle has a lot more weight than the rear of the vehicle and therefore will cause the front tires to wear more if not rotated regularly. You could also have loose steering parts or worn out suspension parts. If you have loose tie rod ends, this can be a safety concern but also throw your vehicle way out of alignment and cause the tires to wear prematurely. Worn shocks or struts can also make a vehicle sit slightly lower which also affects the camber part of your alignment and can wear the inside edges out quickly. All of these components are recommenced by Fleet Doc to be checked every oil change to monitor any sort of wear. Shocks and struts are recommended around 90,000 miles regardless because the gases inside the shocks or struts discharges over time making them weak.