Air pressure

[Jake21]

I was running some numbers and looking for confirmation. My axle weight is 12000 on the front and 20000 on the rear non tag.

I am running Micheline XZA2 295/80 r22.5

According to Micheline's website I show that I should inflate to 90 psi on the front and 80 on the rear.

Does this look right to you? Does anyone go higher than the recommended pressure?

Thanks for your input.
Jake

[xctraveler]

I generally take the tire mfg recommendation and add 5 psi for margin. However without having corner weights I add 10 psi because I have no idea how far off my side to side balance might be. With corner weights use the weight of the heavier end of the axle to determine inflation for all tires on that axle, then go with whatever extra you might want. In the high temperatures we are experiencing today, I might run a bit higher than mfg recommendation to allow for a cooler morning the next time I roll. The recommendation is for ambient temps before you move the coach, but I don't want to fool with the pressure, just because the morning was 20 deg cooler than when I topped them off last.

[Steve Ownby]

Yes, those inflation pressures are correct. It wouldn't hurt to increase 10% to allow for any side to side over weight. The chart is the minimum psi required to carry the weight.

[Dr4Film]

Originally Posted by Jake21

Does this look right to you? Does anyone go higher than the recommended pressure?

Thanks for your input.
Jake

Until you actually have the coach weighed for corner weights, I would run at the recommended high air pressure rating for the tire AND the wheel. Remember that one may be different than the other.

Once you know your corner weights, then you can adjust down from there based on the weight chart you have from the scales and the tire pressure chart for your specific tires.

You can use either one of the forms I have supplied attached to this post for entering your weights and calculating your air pressures needed.

Dr4Film ----- Richard

[Alan24601]

My wheels are marked 120 psi max. and when the tires warm up the pressure can exceed 120 psi. It seems impossible to have the inflation pressure correct for the weight and not exceed wheel ratings for my front tires. I am looking at Michlen tires instead of Good Year and it appears they would cause the problem to be a bit worse because they require more air to carry the required weight. Currently G670 275/70/R22.5. ??

[Steve Ownby]

The max pressures both for the tires and the wheels are cold pressure only. Don't be concerned with the on the road hot pressure. They are understood.

[GaryKD]

Hi Alan24601,
I have the same size tires as you (load range J). I do not understand how you can run 120 PSI in the tires. I am at 20K on the rear axle and Michelin says 90 PSI. 20K should be the largest axles made for a coach. I am at 12K on the front axle and Michelin says 95 PSI. What are the weights you are carrying?

[Alan24601]

The front factory pressure says 115 psi cold and 95 psi for the rears.

[Alan24601]

Originally Posted by Alan24601

The front factory pressure says 115 psi cold and 95 psi for the rears.

Loaf range H for the current tires.