What is the Difference Between ST175/80D13 and ST185/80D13 Tires and Load Range C and D
Updated 07/29/2024 | Published 06/23/2010 >
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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.

Product Page this Question was Asked From
Loadstar ST175/80D13 Bias Trailer Tire - Load Range D
- Trailer Tires and Wheels
- Tire Only
- Bias Ply Tire
- Load Range D
- 175/80-13
- 13 Inch
- M - 81 mph
- Kenda
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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
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