We have the same rig; bought new. The original GY Marathons lasted for about 20,000 miles with no problems but were on their last legs when we replaced them. We keep close eye on air pressure and speed below 65. Two were in process of tread separation and the other two were showing uneven wear. We were just real lucky to make it as far as we did. G rated Sailuns at 110 psi seem to roll easier and temp stays within 10 degrees of ambient temp. Didn't have monitor on the GYs; probably would have been scared to death of them if we did.
|