I had a set of Goodyear Marathon 205/75/15-C's on my approximately 7000lb. , 25' Nash Travel Trailer. They were the older style Marathons.
I was, easily, able to upgrade to 225/75/15-D tires. They are only slightly larger and fit well into the tire wells.
The older Goodyear's were made with steel and polyester belts. When they got hot, the belts would expand and sometimes separate and explode. Goodyear had a real problem with a lot of their tires coming apart.
To correct this problem, they started adding a belt of nylon on the outside of the tread belts. The nylon, aparently, does not expand when it gets hot like the polyester and steel does. Therefore, the nylon acts like a "girdle" on the belts, holding everything together. This new design seems to be working because you don't hear that much about trailer tire separations and blow-outs, anymore.
The problem, now, with the Goodyear Marathons is their cost. Kind of high. But, you are paying for their advertising and the "blimp".
Another option is to go to the Towmasters by Greenball. They are made, in Canada, by Goodyear on the same assembly line using the same materials as the Marathons, just with a different name printed on the sidewalls. My friends and I have been using them for a couple of years, now, with absolutely no problems. I've personally done a 6000+ and an 8000+ mile trip on mine plus many trips around the Southwest U. S.
If you can find the local Towmaster distributor in your area, sometimes they will sell to the general public. The distributor in my area does and is a lot cheaper. I got mine for $62/ a piece. Much cheaper than the Goodyear's and the same tire.
By the way, my old set of Towmasters is still fine. I'm just going to put them on another trailer I have to sell.
I hope this information helps you. None of my friends or I have had any problems with the Towmasters and as I said, I bought them, again.
Joe F. (Buffalo)
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