I was going to switch from the ST (Special Trailer) tire to the Michelin LT (light truck) tire for my Airstream, but found that it is no longer made for 15″ wheels. So, I would have had to go to the additional expense of purchasing 16″ wheels to mount LT tires.
If you are considering switching, first check out the new Carlisle Radial Trail ST tire. It has an 85 mph speed rating as opposed to the 65 mph speed rating of nearly every other Special Trailer (ST) tire. The lower speed rating I believe has been one of the major causes of ST tire failure. It only takes one minute or less travel in excess of that rating to damage the tire, so Carlisle has addressed that with their new design.
I bought the Carlisle Radial ST225/75R15 for my 32′ Excella (GVWR 8,300 lbs.) and just returned from a 3,000 mile trip. They preformed well and though I normally only tow at speeds below 65, there were several segments of the trip when I exceeded that. There appears to be little wear on the tires and they are looking really good, whereas I replaced my previous Goodyear Marathons with only about 7,000 miles on them because of poor wear patterns, and indications of impending tread separation. That was despite taking very good care of the Goodyear tires, as I used the Pressure Pro tire pressure sensors, never drove over their speed rating, used tire covers when not in use and even put the trailer on jack stands when storing to keep the tires off the ground.
The Carlisles though, do appear to be performing much better. I bought them from Discount Tire, $99 each plus replacement, fees, and balancing.
But now for my review of the Michelins I now have on my 3/4 ton 1985 Chevrolet Suburban. It is a good tire and appears to be wearing and holding up well with only the 3,000 miles on them. I did have to go with a slightly wider and lower profile to find a fit for my 16″ rims. I thought that would be a good thing to do anyway, for better performance, and the carrying capacity was not reduced by doing that. I was hoping also for a more comfortable ride and the tires have done that, except for one disconcerting characteristic – the more flexible sidewalls give a more pronounced sensation of sway, especially when towing. So, the jury is still out on these tires as far as I’m concerned, but perhaps I’ll eventually get used to that unpleasant effect.