Can 145/R12 Tire Be Replaced with 15" Tire?

Question:

Kenda Karrier S-Trail ST145/R12 Radial Tire w/ 12inch White Spoke Wheel - 5 on 4-1/2 - LR D Can I go to a 15inch tire and wheel combo with this bolt pattern? If so what would be the # for it

asked by: Herbert

Expert Reply:

The Kenda Karrier S-Trail ST145/R12 Radial Tire w/ 12" White Spoke Wheel - 5 on 4-1/2 - LR D # AM31199DX you're looking at has the same bolt pattern as the larger Karrier ST205/75R15 Radial Trailer Tire with 15" White Spoke Wheel - 5 on 4-1/2 - Load Range C # AM32395 so they will technically fit your hub but I do have a few other things for you to consider.

The first thing is the size of the tire itself. Your current 12" setup has an overall diameter of 21.3" while the 15" option has an overall diameter of 27.1" which means you're losing about 3" of clearance inside your wheel well.

The other thing is your weight rating. The 12" kit is rated at 1,220 lbs at 65 psi while the 15" system is rated for 1,820 lbs at 50 psi so you're jumping up quite a bit in the weight rating and that can cause trailer bounce with the tires filled up to specs.

expert reply by: Jon G