skyking8 Report post Posted May 5, 2011 I have a friend who is about to replace the tires on his 40-foot motorhome. It is of different manufacturer than mine, but about the same empty gross weight. His tires are 255-R80-22.5. Mine are 275s. The difference in load ratings for the dullies is 2,000 pounds, which I would think is significant. I suggested that he get a good all around weighing of the rig and then compare load charts. His are original tires, but I am wondering if he is undersized. Share this post Link to post Share on other sites
garykd Report post Posted May 8, 2011 Hi skyking8, The Gross Vehicle Weight Rating (GVWR) and Gross Axle Weight Rating (GAWR) are the keys to tire size. If the tire size is capable of handling these two weights, the tires are not undersized. Share this post Link to post Share on other sites
skyking8 Report post Posted May 10, 2011 Thanks. I will pass that along to him. He is in the process of buying new tires. Share this post Link to post Share on other sites
tbutler Report post Posted May 10, 2011 One of the considerations in changing tire size is to make sure that the new tire size will allow proper spacing between the dual tires. If the new tires are wider it will reduce the space between the dual tires. This spacing is critical for maintaining proper cooling of the tires. In a worst case scenario the tires would kiss when in contact with the road. This will result in tire failure in a short period of time. Share this post Link to post Share on other sites
