tire pressure

chompchomp wrote:
I have an Itasca Sunova 35j, and posted on the driver's side of the coach it says 80 psi cold all tires. I have 6 19.5 Michelins and on the sidewall it's stamped 120 psi cold. I've always split the difference on the road. If we're at 100 psi all around, we're rolling.

I'm just curious how the rest of you navigate that; I mean 40 psi is a big discrepency. Thanks for any feedback.

the 120-psi on the tire is the maximum pressure the tires are rated for. and while you can inflate them to the max the result may be a very hard ride along with possible handling issues.

the 80-psi on your placard may be the optimal air pressure for the RV's weight when it left the factory or for the GVWR (gross vehicle weight rating) of the MH. using this air pressure will result in a much better ride but it still may be too low or too high for your MH's actual weight.

the proper way to determine the correct pressure for each tire is to load the MH as you would for a trip and then take it to a certified scale to get weighed. loading includes full fuel, lp and fresh water tanks, food, clothing, supplies, pets, people and other stuff. individual corner weights are best but indiviidual axle weights will do. once you know the axle weights and have compared those weights to the published GAWR (gross axle weight rating) for your MH (to be certain neither axle is overweight) consult the Michelin tire inflation guide (available online). this will show the correct inflation for the weight you're carrying for the tires on that axle.

you can add any amount you like to the recommended pressure up to the tire's max. some folks add 5-10 PSI for peace of mind, some don't. you can add but you can't subtract, the rule is....inflate to the minimum pressure for the load being carried.