I've a 26 foot travel trailer and have gone through my share of tires on it. I use a 205 x 15 radial on the trailer and have found that no matter what type of trailer tire you use they are only good for 5 years. I even had a spare that had never been used but was 7 years old blow out after only 75 miles. Lost three tires on a 200 mile trip that year and they all were over five years old. Goodyear Marathon tires are about the worst, I've used Gladiators and a couple other brands but have never had any trailer tire last over five years. Don't know if this helps but good luck with your selection.