Changing from a 13 Inch Trailer Tire and Wheel to a 14 Inch on 3500 Pound Trailer

Question:

The current tires on my single axle camping trailer are 13, bias ply load range D. I want to switch to 14inch radial tires but all I see is load range C. After looking at the carrying capacity of the tire, it would appear that a 14inch C has similar capacity as a 13inch D. My camper has a gross weight of 3500 lbs, so I have to be careful. Why is the dual rating less? I should be looking at the single rating, right? My trailer has only two tires on it. Im doing this because I have the room to raise the trailer up slightly which will help me, I want radials, and the 13inch tires are difficult to find if I have a blowout on the road.

asked by: Robert I

Helpful Expert Reply:

Unless your trailer has dually wheels then you would need to look at just the single tire capacity. On dually wheels the weight isn't exactly always distributed evenly so the lower capacity compensates for that so that no one single tire in the setup is overloaded.

You can go from a 13-inch tire and wheel to a 14-inch provided there is space enough all around the existing tires to go to the larger size. There are 2 common 13-inch trailer tire sizes: 175/80-13 and 185/80-13.

If you go to a 205/75-14 it will be about 2-1/4 inches taller than a 175/80-13 and about 2 inches taller than the 185. As far as width the 14 inch will be 1-3/16 inches wider than the 175/80-13 and about 13/16 inches wider than the 185. If you have the space, then you can go to a 205/75-14 tire and wheel such as # TTWA14RWS if your bolt pattern is 5 on 4-1/2.

expert reply by: Michael H