Community Forums

Lizzythelady · 02-24-2016, 06:42 PM

The dealership put 80p..s.I. In tires. The specifications on cab wall say 90 p.s.I. cold pressure. I am probably at one third of maximum. Weight. Does anyone know what the good. Pressure should be? Going on long trip Saturday , new class a with Michelin xrv tires. Don't want to beat them up! Thanks much! Lou

zorro2kita · 02-24-2016, 06:58 PM

You need to weigh the coach at a truck scale facility to determine how much tire pressure is needed to support the weight on each axle --

There are numerous threads about this topic -

Michelin has a great website that can explain the issues involved -

This is an important aspect of the Motor Coach experience - get it right the first time !!

larrykathy · 02-24-2016, 09:57 PM

FWIW, I run 90psi in all tires, even though the mfg sticker says 85.
Have fun on your trip.

mojoracing · 02-24-2016, 11:46 PM

fwiw, mine vary from 75 to 85 depending on how im loaded on my 35k. After weighing it one time while I had my 20' enclosed trailer and full water i think the backend had to be bumped to 90 one time

Mr_D · 02-24-2016, 11:54 PM

The pressure given on the Federally required sticker is for the rig as loaded to it's capacity and is the safest to use if you haven't weighed it yet.
Although in our case County Coach says to run the sticker pressure all the time.

Quote:

Country Coach Tire Inflation Policy
Tire Industry Changes
The tire industry, as a whole, has changed its traditional stance on adjusting cold tire inflation pressure for RV tires installed on recreational vehicles and buses. Previously, tire manufacturers supported a policy where tire inflation could be adjusted according to the actual loaded weight of the vehicle. Now, the major tire manufacturers recommend that medium duty truck tires be maintained at the pressure that corresponds to the Gross Axle Weight Rating for the axle to which they are mounted. To make this recommendation uniform across the industry, tire manufacturers strongly urge the consumer to keep all tires inflated to the pressures recorded on the Federal Tire Label.

Tire Inflation
Country Coach recommends that the cold tire inflation pressures should at all times be maintained at the inflation pressure(s) recorded on the Federal Tire Label. There are no acceptable circumstances where tire inflation pressure(s) should be reduced below that pressure recorded on the Federal Tire Label.

computerguy · 02-25-2016, 06:34 AM

Quote:

Originally Posted by Mr_D

The pressure given on the Federally required sticker is for the rig as loaded to it's capacity and is the safest to use if you haven't weighed it yet.
Although in our case County Coach says to run the sticker pressure all the time.

Hmmm, I have a 35K and the sticker shows max is 90psi. I looked at the Michelin website and it shows I should run at 75 based on my weight. In addition, 90 psi is wayyyyyyyyyyyyyy over the weight allowed according to the Michelin inflation/weight guide.
Dealer delivered it with 90 and it drove horrible. 75 and it handles much better.
It bites that they make all this so confusing. It shouldn't be. My 2 cents and IMHO.

Gary RVRoamer · 02-25-2016, 03:47 PM

If you know the weight and monitor it for changes, you can use the tire maker's inflation table values. If you don't have that indo, use the RV placard, which assumes maximum load on each axle. It's not safe to guess low, so don't try to guess.Get a scaled weight, or use the placard defaults.