What is the Modern Tire Size for H78-15 Trailer Tires

Updated 03/27/2025 | Published 12/10/2013

Question:

My tires on my tv are: H78 15st What tires would you recommend. We inherited this trailer from my I laws

asked by: Shawn D

Expert Reply:

The modern tire size for the H78-15 tires is 225/75-15. The Karrier ST225/75R15 Radial Trailer Tire, # AM10256, would be a suitable replacement tire. Keep in mind, this is a Load Range D tire which is an 8 ply tire with a load capacity of 2,540 lbs at 65 psi.

I recommend checking the weight capacity of your axles before purchasing a tire. It is important to choose replacement tires that equal or exceed the weight capacity of your axle. Also, it is recommended to replace both tires on an axle at the same time, especially if both of the tires on the axle are H78-15 tires.

expert reply by: John H

Brian

3/22/2025

So putting 225/75/15 tires on my camper will be ok instead of the H78-15-st ?

John H.

3/27/2025

@Brian Yes, they are basically the same size, so you won't have any issues with rubbing or fit. As I mentioned above, you'll want to keep an eye on weight capacities, but other than that they are basically the same size tire. It sounds like you might have an old camper. I'm a fan of vintage campers. What do you have?