Replacement Tire Availability to Replace an E78-14

Question:

I have a 40 year old travel trailer I am redoing. When I purchased it, there was a destroyed E78-14 tire and an old 13inch tire. I do not know the weight and it is 14ft x 7ft. A ST 205-75-14 is too large. I found out that the modern day equivalent is a 195-70-14. I can not find this in a ST tire. I have found ST185-80-13. How do I decide if a 13inch is safe I assume 14 is better than 13?. I appreciate any help you can give me on what size I need. Thank you.

asked by: Robbin M

Expert Reply:

The ST185/80-13 tire like part # AM1ST79 is going to be 24.4 inches in overall diameter. The tire size ST 205-75-14 that you tried already is 26.3 inches tall so the 185/80-13 would be right at 2 inches shorter in diameter.

Assuming your bolt pattern is 5 on 4-1/2 inch the part # AM3S331 would be for a wheel and tire in the ST185/80-13 size and has a 1,725-lb maximum load at 65 psi. You would need to determine the overall weight of the trailer first to be absolutely certain you have enough tire/wheel capacity. 14 inch wheel setups typically have higher capacities than 13 inch setups. But other than that there really isn't a huge advantage.

expert reply by: Jameson C