Speed Rating and Tire Pressure Recommendation On a ST175/80-13 Tire

Question:

speeds on the road are 75mph I have a coleman popup at this time I air up to 62 psi and only do 70 mph 175 x c load 13 inch. what do think?

asked by: Mike

Expert Reply:

The speed rating on all special trailer tires (ST) is 65 miles per hour. It is not recommended to run a trailer tire at a higher speed than 65 miles per hour due to the heat buildup that will occur inside the tire and cause the tire to break down and cause the tire to fail.

Special trailer (ST) tires should be inflated to the maximum air pressure that is stamped on the sidewall of the tire. It will be stamped with a designation of maximum load at a maximum psi.

On a ST175/80-13 tire that has a load range of C, like the Kenda Tire and Wheel, part # AM3S160, you will want to run the maximum of 50 lbs of air pressure. That will give you a total weight capacity of 1,360 lbs per tire or 2,720 lbs for 2 tires on your camper. Increasing the tire pressure above the maximum will not increase the weight capacity of that tire. If you need higher capacity the ST175/80-13 load range D tire, like the Kenda Tire and Wheel, # AM31994, would run at 65 lbs of air pressure and will have a total weight capacity of 1,610 lbs per tire or 3,220 lbs for 2 tires.

I am including a link to a FAQ page that will answer frequently asked questions on trailer tires.

expert reply by: Jeff D