Luxury Coach Lifestyles - View Single Post - Keeping the best Tire pressures on a motor coach.
View Single Post
Old 05-05-2013, 09:19 PM   #10
77newell
Senior Member
 
Join Date: May 2008
Location: Just North of Detroit, a surprizingly great city
Posts: 380
Default

Hi Ken: if you plan to use the inflation pressures provided by those that responded to your original post I would suggest you consider a broader base of information.

For our heavy vehicles the minimum tire pressure is based upon the actual loaded weight of the heaviest end of the axle the tire is supporting. Using that weight you then go to the inflation table provided by the tire manufacturer for the particular tire size and load range rating of the tire installed on the axle in question. Since different though similar coaches may utilize different tire sizes and load range ratings you need to use your particular tires to determine pressures. The pressure in the table is the minimum necessary to carry the weight reliably for the life of the tire. You may decide to go higher, but no higher than the table indicates for the load range rating of the tire. The higher the load range rating the higher the maximum allowed tire pressure together with higher load capacity with the higher pressure.

Then you need to maintain that minimum cold tire pressure as measured with the tires cold. You also critically need to know the maximum speed rating for your particular tires. Exceeding that speed puts the carcass in jeopardy of failing if driven above the tire's speed limit.

Finally, I worry that we are missing something if we are having tires fail early in their life. I can find no document on manufacturer's websites indicating any reduction in expected tire life as the load on the tire increases as long as the tire is designed to carry that weight and tire pressure is maintained appropriately. Unless the tire carcass was physically injured, trucker's experience is that we should expect to run these tires reliably for at least the life prescribed by the manufacturer. If that is frequently enough not our experience then I believe that it is either the application into which the tire is placed or something we are doing with maintenance of pressure that is likely leading to that outcome.

This posting sounds uncharacteristically stern for me and I simply lack the ability at the moment to make it just as informative without the inherent unfortunate tonality. I'm certainly in no position to tell anyone what do do in this ambiguous arena of tire pressures. Hopefully you can simply take what I've written as my take on the tire pressure situation and infer nothing further.
__________________
Jon and Alie Kabbe
Started with 77 Coach
Now have 39' 93 coach
2007 civic toad
77newell is offline   Reply With Quote