Clearance Required to Upgrade from ST155/80-13 to ST175/80-13 Trailer Tires and Recommendation

Question:

Have a boat trailer with size st 155 r 80 13 tires that need replaceing cant fine that size anymore trailor is a 98 closest size is a st 175 r80 13 will it rub and if so what can i do. Thank you

asked by: Bob G

Helpful Expert Reply:

The general rule of thumb is that to have enough clearance for your trailer to travel over bumps and potholes, you want to have at minimum of 3-4 inches between the tire tread and the fenders. You also want at least 1-2 inches between the tire sidewall and inside of the wheel well.

Your existing ST155/80-13 tire is 6.1" wide and has an overall diameter of 22.7". An ST175/80-13 is 6.9" wide has an overall diameter of 24", so it's going to add about 7/16" of width on each side and 5/8" on the top and bottom, which is not much, so you should be fine. My recommendation in this size is the Taskmaster Provider # TTWTRTM1758013C. It's a radial tire with an 81 mph speed rating, which will stay cooler and last longer than your old bias ply tire.

expert reply by: Carla M