What is the Difference Between ST175/80D13 and ST185/80D13 Tires and Load Range C and D

Question:

what changes will I notice if I change from a ST175-80D13 to a ST185-80D13? I am pulling a galvinized trailer with a 16 ft. aluminum boat which I load heavy for fishing trips. Also what differences will there be from a C load range to a D load range?

asked by: Chuck

Expert Reply:

The ST185/80D13 trailer tire will be 10mm wider and the tire will go from 24 inches tall to 24-1/2 inches tall. Just make sure you have space to accommodate the extra height and width so that you do not end up with tire rub.

Load range C tires have a ply rating of 6, and load range D tires have a ply rating of 8. Load range D tires are bit heavier built and have a higher weight capacity. The ST175/80D13 tire you were looking at is load range D and can bear 1,610 pounds at 65 psi. An ST17580D13 with load range C, like part # AM1ST76 can bear 1,360 pounds at 50 psi.

I have linked an FAQ on tires that shows how to measure a tire and determine what size and type of tires you have. Also linked is an FAQ on common tire questions.

expert reply by: Patrick B

Lindag

5/31/2020

I currently have a utility trailer with ST185/80D13 5 bolts tires on it, can I replace these with ST175/80D13? I'm thinking the only difference will be the trailer will be lower to the ground, possibly affecting the height it attaches to the hitch as well? Thank you.

Chris R.

6/3/2020

You can absolutely make this change. An ST175/80-13 tire like the Kenda # AM10210 will only be about a 1/2" taller in diameter, and only half of this (1/4") will actually affect your trailer's height. So it will lower your trailer by a REALLY small amount.