I just bought some new tires for my trailer and chose radials over the bias ply tires that came on the trailer. I didn't think much about the new tires until my first trip to the lake. My trip is about 220 miles round trip and I'm estimating I used 2 to 3 gallons less fuel than I normally do. This was based strictly on the gas gauge not actually checked, but I will check it next trip. I talked with a tire guy and he said this was possible because the radial tire has less rolling resistance than a bias ply tire. Anyone seen this before?
As it turns out, Carlisle is aware of the problems. But it seems (at least according to the person that I talked to) that they've only had problems out west. I just had a complete tread separation on a tire that was all of 11 months with maybe 5,000 miles. Probably closer to 3,500 really. After calling the trailer manufacturer and then Carlisle they shipped me 5 brand new tires at no cost.
So if you've had problem with tread separation you might want to give them a call and complain if needed until they take care of the problem.
They replaced mine with ones that are rated for a heavier load. It turns out that the Carlisle tires I have are manufactured by Goodyear. Anyway, the news ones are supposed so solve the problem and the slight damage to the trailer is being covered by Goodyear. So I just have to pay to have the tires mounted and balanced.