Comparing ST175/80-13 and ST185/80-13 Trailer Tires for a Coleman Casa Grande Trailer

Updated 07/23/2013 | Published 07/19/2013

Products Featured in This Question

Karrier ST175/80R13 Radial Trailer Tire with 13" White Wheel - 5 on 4-1/2 - Load Range D

(1565)

$158.73

Karrier ST175/80R13 Radial Trailer Tire - Load Range D

(2300)

$104.94

Loadstar ST185/80D13 Bias Trailer Tire - Load Range D

(3847)

$128.22

Question:

I need 2 new tires for my Coleman casa grande and Ive been reading some different opinions about what to use. I currently have ST185/80/D13 on it. Ive been told the more common 175/80/R13 will be fine. I read a previous post about the difference between bias and radial and Im going to go with the radial. Now, is it wise to go with a smaller tire? They said the load rating would be fine. Should I try to get a 185/80/R13? Camper specs -2400lbs dry. Some people said with full water tank, propane and gear 3000lbs+. Thanks for your help.

asked by: Kevin

Expert Reply:

First, you should go with the tires that are recommended by the trailer manufacturer. This information should either be on the trailer tongue or frame somewhere or in the literature for the trailer.

Trailer tire sizes ST175/80-13 and ST185/80-13 do fit the same size wheels and are about the same height (24.1 inches and 24.4 inches respectively). The 185s are wider by 0.394 inches.

If you went with the smaller ST175/80R13 then for up to 3,000 pounds gross trailer weight you would need a load range D like # AM10210. But if you stay with ST185/80D13 you are limited to a bias trailer tire # AM1ST79. Bias ply tires are good for more so-called offroad applications but radial tires run cooler.

I have included a couple of FAQ article links on trailer tires for you.

expert reply by: Michael H