Can Trailer With Existing 205/75-15 Tires Increase Tire Size to 235/75-15

Question:

Can I use a 235/75R15 tire on a trailer that currently has a ST205/75D15 tire on it?

asked by: Blake

Expert Reply:

It'll depend on how much fender/frame clearance you currently have.

Going with a larger tire such as the ST235/75-15 # WST54FR tire would increase the tire diameter by about 2 inches and the width by about an inch. This will move the top of the tire about 1 inch closer to the inside top of the fender or wheel well and about 1/2 inch closer to the trailer frame to the inside.

With the trailer loaded up as you'd typically have it, you want to see 4 inches of clearance above the tire (3 inches at an absolute minimum) and about 2 inches between the inside of the tire and the trailer frame. So, I'd recommend measuring the existing clearance above and to the inside of your current tires. If adding one inch of height and 1/2 of width to the inside of the tire would still allow the clearances mentioned above, you could certainly increase to a 235/75-15 tire.

expert reply by: Mike L