Tire Inflation Dilemma
I recently had a stem replaced on one of my real duallies due to a slow leak. When the guy inflated my tires he set the rears for 80PSI and the front for 65PSI. He said all Class Cs should have 80PS...
Forum Discussion
On our E450 ~11,800 lb. 24ft Class C with LT215/85R16 Load Range E M&S tires, I use around 80 lbs. in the rear and around 65 lbs. in the front.
Comments regarding my ignoring of the tire pressure loading charts and using 80 lbs. in the rear dualles are:
1. I want our Class C to be configured for it's chassis maximum capability/capacity in the rear at all times.
2. The resulting ride in the rear was at first terrible on highway bumps and cracks.
3. I later mitigated that rough ride in the rear by installing special dual-action shocks back there.
4. I wanted the sidewalls in the rear tires to flex as little as possible to keep heating at a minimum in all ambient temperatures... and 80 lbs. pressure helps keep the sidewalls stiff. Excessive sidewall heating causes material failure and/or cracking sooner in tires.
5. I wanted the sidewalls in the rear duallies to be as far apart as possible - helped by keeping the tires stiff - so as to help provide a bit more room for air flow between the duallies in high ambient temperatures.
6. I wanted the improved vehicle lateral stability in curves and cross winds that stiffer tires provide.
7. In over ~12 years of travel I've noticed no uneven wear laterally across the tread area in the rear tires from using higher pressure than the weight charts recommend.
8. I keep the spare at 80 p.s.i. pressure so I can use it as is in the rear, or merely let out 15 lbs. of pressure from it if needed in the front.
Comments regarding my ignoring of the tire pressure loading charts and using 80 lbs. in the rear dualles are:
1. I want our Class C to be configured for it's chassis maximum capability/capacity in the rear at all times.
2. The resulting ride in the rear was at first terrible on highway bumps and cracks.
3. I later mitigated that rough ride in the rear by installing special dual-action shocks back there.
4. I wanted the sidewalls in the rear tires to flex as little as possible to keep heating at a minimum in all ambient temperatures... and 80 lbs. pressure helps keep the sidewalls stiff. Excessive sidewall heating causes material failure and/or cracking sooner in tires.
5. I wanted the sidewalls in the rear duallies to be as far apart as possible - helped by keeping the tires stiff - so as to help provide a bit more room for air flow between the duallies in high ambient temperatures.
6. I wanted the improved vehicle lateral stability in curves and cross winds that stiffer tires provide.
7. In over ~12 years of travel I've noticed no uneven wear laterally across the tread area in the rear tires from using higher pressure than the weight charts recommend.
8. I keep the spare at 80 p.s.i. pressure so I can use it as is in the rear, or merely let out 15 lbs. of pressure from it if needed in the front.
