Can a ST225/75D15 Trailer Tire be Swapped out for a ST225/75R15

Updated 05/28/2013 | Published 05/22/2013

Question:

we bought a 5th wheel camper that has ST225/75D15 tires on it and our other camper we had put ST225/75R15 on it. They are brand new tires. Can we replace the D15 with the R15

asked by: Terri

Expert Reply:

The difference between the ST225/75D15 and the ST225/75R15 is the way the tire is constructed. The D in the ST225/75D15 size means that it is a bias-ply tire whereas the R in the ST225/75R15 means that it is a radial tire.

Radial tires are preferred because the tire has more flex and will allow for more ground contact. That will improve traction and better tread wear. It also gives the radial tire better stability. Radials will also run cooler.

So long story short, you could swap out the bias-ply rated tires you have for radial tires of the same size without any problems. You actually would be better off this way. Check out the FAQ article I attached on trailer tires also.

expert reply by: Jameson C