Community Forums

rjsupersonic · 03-24-2015, 11:14 AM

I replaced all my tires 2 years ago with Michelin XRV {245/70 R 19.5 F} My coach weighs 20,200LBS loaded. I was running 95PSI in the rears and 90 PSI in the front. I just happened to recheck the Michelin inflation tables and discovered I was high on my pressures. Per the table I should be around 80 or 85 all the way around . I just wonder if the tables changed in the two years?? I guess my ride will be a bit smoother now. I will get all four corners checked eventually but for now using the CAT scale readings. I also spoke to a Michelin dealer and he said I may notice a slight change in my MPG with the lower pressures. I anyone is running the Michelin tires they may want to check their inflation chart available at the Michelin website.

Hikerdogs · 03-24-2015, 12:58 PM

My 2013, 2014, and 2015 Michelin inflation tables all show 95 psi the maximum pressure for the XRV {245/70 R 19.5 F}. At that pressure they're supposed to be able to carry 4080 lbs. as singles and 7720 lbs. as duals.

At 80 psi they're supposed to hold 3640 lbs. as singles and 6830 lbs. as duals.

At 85 psi they're supposed to hold 3740 lbs. as singles and 7030 lbs. as duals.

All 3 charts have the same information.

rjsupersonic · 03-24-2015, 02:35 PM

my front axle is 6740lbs and the rear is 13440. I was looking the single and duel axle chart which states up to 7280lbs would be 80 PSI and up to 13660 lbs would be 80 psi as well. Same numbers x 2. I was just going by axle weight.

Ray,IN · 03-24-2015, 06:33 PM

Quote:

Originally Posted by rjsupersonic

I replaced all my tires 2 years ago with Michelin XRV {245/70 R 19.5 F} My coach weighs 20,200LBS loaded. I was running 95PSI in the rears and 90 PSI in the front. I just happened to recheck the Michelin inflation tables and discovered I was high on my pressures. Per the table I should be around 80 or 85 all the way around . I just wonder if the tables changed in the two years?? I guess my ride will be a bit smoother now. I will get all four corners checked eventually but for now using the CAT scale readings. I also spoke to a Michelin dealer and he said I may notice a slight change in my MPG with the lower pressures. I anyone is running the Michelin tires they may want to check their inflation chart available at the Michelin website.

Those inflation/load charts show the ablsolute minimum air pressure to support the corresponding load.
Now, Michelin, Goodyear, Firestone, etc are members of the Rubber Manufacturers Association=RMA, their pdf says a bit differently. You may read Ch 4 which pertains to MH tires here: RMA pdf (pg 55)

rjsupersonic · 03-24-2015, 11:28 PM

Per the chart I should be at 80 PSI all the way around, I think I will try them at 85 psi I would rather be slightly over inflated than underinflated. Once I get the four corners checked I can adjust accordingly. Good information thanks.

Ray,IN · 03-26-2015, 06:12 PM

Quote:

Originally Posted by rjsupersonic

Per the chart I should be at 80 PSI all the way around, I think I will try them at 85 psi I would rather be slightly over inflated than underinflated. Once I get the four corners checked I can adjust accordingly. Good information thanks.

Running tires at maximum load for the corresponding pressure( 100% load capacity) is exactly what owners of trailers have complained about for years; very unreliable tire longevity. The RMA states to never run less than placard required air pressure.