I had my coach weighed full, right after I bought it. Based upon the Goodyear Tire Load/Inflation Chart, I should be running 90 lbs. in all six tires. After reading several different threads about tires, a lot of people with a similar size coaches seem to be running a higher PSI.

I like the compliant ride of my coach as is, but I'm wondering if a higher PSI would be safer and/or give me a little better fuel economy. Any thoughts?

Craig

Typically a higher pressure will reduce rolling resistance and improve fuel economy, run a little cooler too. Too high a pressure will result in a more harsh ride and wearing out the center tread of the tire. An old trick is to run a chalk line across the tire tread and check it for wearing off equally at different pressures. You might find a higher pressure than what the charts show but still have full tread contact with the road surface.

Fleetman.

That is a great trick!!

Im getting some chaulk......

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Too high a pressure will result in a more harsh ride and wearing out the center tread of the tire

This can also effect your steering and control.

Recommended at the Freightliner school was the tire manufactures recommended pressure plus 5 lbs for a safety factor. That's what I run in mine. Rides good, handles good and I can't tell any difference in fuel mileage than when they were at a higher pressure.

Keep in mind the reference chart suggests the bare minimum at that weight. You may want to bump up to the next weight recommendation especially if you are not loaded as if you were traveling. I wouldn't increase tire pressure. You should gain maximum fuel economy based on the Goodyear recommendation.

Remember, to high pressure as well as to low pressure can cause overheating which is the number one cause of blowouts. Please don't go above the manufactures recomended high PSI on your tire just to get more MPG...........And check PSI before you've driven to get an accurate reading. Motor safe!

During a recent trip to Spartan, the tech suggested different air pressure per place than the decal by the driver's seat. Front: 105, drive axle 85 and tag 85. Decal suggested 115, 85 and 75 on tag. They warned me that 75 could result in rolling the bead and damaging the tire. His suggest air pressure was based on Michelin specs. Not sure why they are different than the specs on the decal.

Michelin has mentioned to me that 85 PSI is the minimum recommended PSI for 22.5 tires. Their PSI charts on their web site confirm this.

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Not sure why they are different than the specs on the decal.

The decal specifies the minimum tire pressure needed to carry the full rated axle load, i.e. the heaviest your RV should ever be. If your coach weighs less than the max, you can adjust the tire pressure downward per the values in the tire manufacturers inflation tables. It is typical for the front axle to be carrying much less than its maximum rated load. Coaches with tag axles may be carrying less on the rears as well, but coaches with a singe rear axle are often loaded up near the limit.

I have just made and interesting discovery. After getting a four corner weight on my rig since we started to full time I consulted the Michelin weight charts and found that I could run 85 PSI in my front tires easily. I aired down as I was running 95 PSI. I left on a 280 mile trip with the new PSI in the tires. I was miserable! The coach wandered all over the highway, and I was worn out by the time I got to the destination. In the morning I aired back up to 95 PSI that I had been running in the front tires. A few days later we pulled out and headed for the next destination. Lo and Behold all was right with the world!!

The conclusion is that although the tire charts listed the "safe" pressure for my tires, the reality was that the sidewalls were much too soft at that pressure and dramaticly increased the wander on the front end. By increasing the pressure the sidewalls are now stiffer and better support the coach.

By the way, the sticker on the coach recommends 110 PSI in the fronts, which is the maximum allowable for the tire. I ran that pressure at first, and the rig felt like a skateboard going down the road. The conclusion is that you need to find the middle ground between good handling and good tire wear. At 95 PSI I am well over Michelin's safe pressure for the weight that I am carrying, but below the max for the tire.

Sarge