Modern Tire Size Equivalent for Replacing F78-15ST

Updated 03/28/2024 | Published 04/18/2017

Question:

my camper tires have f78 15 St on them I cant find them can I use 215 70 15 tires instead

asked by: Jesusa C

Expert Reply:

The Taskmaster ST205/75R15 Radial Trailer Tire # TTWTRTM2057515C would work well for you. It is the same size as your f78-15st and is a radial.

A radial tire flexes more than a bias tire, giving it better ground contact, traction, stability, and tread wear.

A radial tire will normally run cooler than a bias ply tire, especially when the tire is under a load. A tire that runs cooler will last longer.

expert reply by: Jameson C

Tyler

3/19/2024

My trailer I just purchased is all steel horse trailer. It's super heavy but also has F78-15st tires on it. It's a dual axle trailer (10 foot long). What do you recommend???

Jameson C.

3/19/2024

@Tyler The Taskmaster # TTWTRTM2057515C I mentioned in the initial answer would work great for you. Do you have any concerns about it though?

Tyler

3/19/2024

@JamesonC yes. Max load is 1800lbs. I'm using a 10 foot horse trailer that is constructed of solid steel. It's a super heavy trailer. I'm not sure tires that are weighted for 1800 lbs (albeit 4 of them) would support a 5000lb trailer with two horses without really stressing the durability of the tires

Jameson C.

3/28/2024

@Tyler So with 4 of those tires you'd have a tire weight capacity of 7,280 lbs. That means you'd have 2,280 lb left over for the weight of your horses or any other tack. So for a higher rated tire in this size you'd want the part # TR20515D which would give you an overall tire weight capacity of 8,600 lb.