Will an ST225/75R15 Trailer Tire Fit In Place of an ST205/75R15 Trailer Tire

Updated 06/02/2014 | Published 05/30/2014

Question:

I have 205 75 15 tires on my travel trailer and wanted to know if 225 75 15 would rub fenders?

asked by: Tim

Expert Reply:

An ST205/75R15 tire size like you have now will have a section width of 8.1 inches and overall diameter of 27.3 inches.

An ST225/75R15, # AM10256, will have a section width of 8.9 inches and overall diameter of 28.4 inches.

So the larger size is 0.8 inches wider and 1.1 inches taller. On the height though only half of the height needs to be considered so it will be 0.55 inches closer to the underneath part of the fender.

If you have more than 0.55 inches (just under 91/6 inches) clearance above the existing tires and 0.8 inches between the side of the tire and the frame then the larger size will fit. Your existing wheels will need to be 15 x 6 inches or 15 x 6-1/2 inches for the larger size to fit the same wheel.

Wheel width can only be measured with the tire off of the wheel and you measure from bead seat to bead seat.

expert reply by: Michael H