I and friends have had late model fivers of various brands in the 12,000# plus range. The Goodyear "Marabombs" would not hold up and we all eventually chose alternate tires whether Goodyear G14's or G rated LT tires like Firestone, Uniroyal, or B F Goodrich makes. You can read pages and pages, and pages of "Marabomb" failures on the heavier RV's. Some times Goodyear stepped up and paid for damage due to blow outs and credit towards alternate tire choices. The key to those instances was keep the tire carcass for Goodyear's inspection. Some of us sold our "Marabombs" to farmers as they use them on low speed farm trailers. The "Marabombs" do seem to work with the lighter RV's around 6,000#.