235x80Rx22.5 tire pressure

[RVluvin]

Michelins, 34' Safaria Simba, 110 max pressure. With out all the axel/tire weighing, what would be a good average tire pressure to run in the hot state of AZ and neighboring states, without sacrificing ride quality?

Thanks.

[Mr_D]

The pressure on the sidewall of a Michelin RV tire and many others is not the "Maximum" the tire should ever have (unlike car tires) it is the minimum to support the maximum rated carrying capacity of the tire.

From page 2 of the 06/07 Michelin RV Tire Guide:

"If you look at the tire's sidewall, you'll see the maximum load capacity allowed for the size tire and load rating, and the minimum cold air inflation needed to carry the maximum load."

From page 6 of the GoodYear RV Tire and Care Guide:

"How much air is enough?
The proper air inflation for your tires depends on how much your fully loaded RV or trailer weighs. Look at the sidewall of your RV tire and you’ll see the maximum load capacity for the tire size and load rating, as well as the minimum cold air inflation, needed to carry that maximum load."

From TOYO:

Q: What are the consequences of inflating the tires to accommodate the actual loads?
A: If the inflation pressure corresponds to the actual tire load according to the tire
manufacturer’s load and pressure table, the tire will be running at 100% of its rated load
at that pressure. This practice may not provide sufficient safety margin. Any air
pressure loss below the minimum required to carry the load can result in eventual tire
failure.

But then they go ahead and publish a weight/pressure chart allowing lower pressure for RV's!!

From the August 2010 Motorhome Magazine "Tread Carefully" tire article:

The maximum load capacity allowed for the size tire and load rating and the minimum cold air inflation needed to carry that maximum load are located on the tire’s sidewall.

[mfire1339]

RVluvin, there should be a sticker on the wall behind driver seat.




Mike

[Wayne M]

Here we go again, it's happy days again....sung to - oh I don't know.

I'm going to sit back and

[Gary RVRoamer]

Use the pressure shown on the placard by the driver's seat. It will probably be a bit more than necessary, but its the too risky to go with less without getting an actual weight. There is no shortcut to the process for determining the proper psi.

If you can't find the federal tire & weight placard by the driver seat, inflate the tires to the psi show on the sidewall for lax load. It will be firmer than necessary, but you should not go lower until you can get a weight.

[GreaTOne65]

After checking the tire pressures on my MH, yesterday, I decided, I just didn't want to trust to luck another 1800 mi. trip back to MI. on them so today I ordered an new set for the duals. IMHO, I would never, ever run less than 110 psi. in any of my tires. Anything less is just askin' for a let down,(pun intended).

[RVluvin]

Thanks all. Found the placard, 95 lb on the single & 90 lbs on the doubles. Previous owner was running between 80 -85 not good.

[CLIFFTALL]

Originally Posted by RVluvin

Thanks all. Found the placard, 95 lb on the single & 90 lbs on the doubles. Previous owner was running between 80 -85 not good.

The PO may have been correct. You have to have the RV weighed to find out. The placard shows the proper psi at max weight for each axle. You may be carrying less and therefore will require less psi.

[Old Trucker]

Originally Posted by RVluvin

Thanks all. Found the placard, 95 lb on the single & 90 lbs on the doubles. Previous owner was running between 80 -85 not good.

Hi rvluvin, In the opinion ol an old retired trucker, I think you got it right.... I see all this stuff about adjusting the air pressure according to the weight of the vehicle.

Had I done this ,I would have wasted so much time and time equals $$$. I could never have survuved in the trucking business financially. How much time would it take to adjust the pressure in 18 tires because I just went from an empty weight of 34,000# to a loaded weight of 80,000# I think 90 to 95 # will do a fine job. The max rating is just that. These are the same tires as used on trucks. You will not max out on tire rating on a motorhome. I am talking about a 22.5 14 ply tire. Good wishes, from the old trucker

[CLIFFTALL]

Originally Posted by Old Trucker

Hi rvluvin, In the opinion ol an old retired trucker, I think you got it right.... I see all this stuff about adjusting the air pressure according to the weight of the vehicle.

Had I done this ,I would have wasted so much time and time equals $$$. I could never have survuved in the trucking business financially. How much time would it take to adjust the pressure in 18 tires because I just went from an empty weight of 34,000# to a loaded weight of 80,000# I think 90 to 95 # will do a fine job. The max rating is just that. These are the same tires as used on trucks. You will not max out on tire rating on a motorhome. I am talking about a 22.5 14 ply tire. Good wishes, from the old trucker

All this " stuff " is what has been generally accepted as the safest and most comfortable ride. RV's are not subject to the kinds of weight variances that your 18 wheeler was. Our CCC is about 5-10% of our total and once loaded doesn't vary that much ( maybe a few hundred lbs.). Over inflation can do damage to tires as well.

[Bob and Inga]

Originally Posted by Gary RVRoamer

Use the pressure shown on the placard by the driver's seat. It will probably be a bit more than necessary, but its the too risky to go with less without getting an actual weight. There is no shortcut to the process for determining the proper psi.

rvluvin,

This works for us and we have the same tires as you, but we run 100 lbs. vs the 95 / 90 on the label. That gives us some fudge room as we don't carry an air compressor. We might need a couple of lbs. of air every year or two.

Bob