What is the Speed Rating for Loadstar ST215/75D14 Bias Trailer Tire

Question:

I was enquiring about the speed rating on your loadstar tyre ST215/75D14. After a replacement tyre,Load range C, loadstar K550 G78-14 , 850kg.

asked by: Trevor

Expert Reply:

The speed rating for trailer tire # AM3S560, is 65 miles per hour. You would not want to go over 65 miles per hour because that will generate more heat. Heat is the number one enemy of tires, especially trailer tires. This is because trailer tires are built with a thicker sidewall that, when overloaded, ran at higher speeds, or under inflated, will generate excessive heat and cause the tire to fail.

The proper replacement size for a G78-14 is going to be a 205/75-14, not a 215/75-14. The 215 tire will be 0.394 inches wider and 0.4 inches taller than the 205. If you have the space all around the old tire for the larger size AND the wheel width is 5-1/2 to 6-1/2 inches measured from bead seat to bead seat then you can use the larger size.

If you want to stick with the 205 tire I recommend # AM10235 which is a load range D rated for 2,200 pounds at 75 psi. And for the same wheel that is on tire and wheel combo AM3S560 that you referenced use # AM20354. These tires are rated for 81 miles per hour. I have included a couple of helpful links on trailer tires for you.

expert reply by: Michael H