Have you noticed that the tires on your trailer are wearing funny? This may be especially noticeable on car trailers (flatbeds) and boar trailers.

Below is (2) charts and some photos to help you diagnose the problem:



Under Inflation – Wear on both edges: 

Under inflation of a tire reduces its tread life by increasing the tread wear on its outside edges, or shoulders. It also generates excessive heat which reduces tire toughness. Finally, it reduces fuel economy through increased rolling resistance because soft tires make your trailer and vehicle work harder. Abnormal tire wear may also be caused by misalignment.

Over Inflation – Wear in center: 

When a tire is over inflated, the center of the tread bears most of the load and wears out faster than the outside edges. Uneven wear reduces the useful life of a tire.

Cupping – Cups or dips in the tread:

Cupping (also called dipping) is most common on front tires, although rear tires can cup as well. It may be a sign that wheels are out of balance, bearings are loose or that suspension parts are worn out.

Inside or Outside Wear: 

If the edges of your tire tread take on a sawtooth or feathered appearance, it’s because of erratic scrubbing against the road. The solution is an alignment correction.

If the inside of tire is smooth or shows signs of excessive wearing  it is likely the result of overloading the trailer.


Some wear issues could be from improper tire inflation. Make sure you’re running the proper tire pressure in your trailer tires.


Tire Size Max P.S.I Cold
4.80×12 90 psi
175/85D13 50 psi
205/75D14 50 psi
205/75D15 50 psi
225/75D15 65 psi
235/80R16 90 psi
235/85R16 90 psi


Photo Examples:

(Wear from being overloaded)

(Wear from being over inflated)

(Wear from being under inflated)

(Wear from wheel locking up or skidding)

(Cupping – see the high and low sections along the left)

More Articles: