lazylizard2 Report post Posted January 27, 2020 I've been running Goodyear G670 (245/70/19.5) and had to replace this year. FMCA didn't offer the discounts on Goodyear, so I went with Michelin XZE (245/7019.5) With the Goodyears I was running 80psi, but at the Michelin tire shop they set the new tires to 100psi. I'm confused and tried looking up the right psi for the tires. Can anyone help Share this post Link to post Share on other sites
wolfe10 Report post Posted January 27, 2020 lazylizard2, Welcome to the FMCA Forum. With your actual axle weights, go to this Michelin website: https://www.michelinrvtires.com/reference-materials/load-and-inflation-tables/#/ If you do not yet have actual weights, look on your GVWR plaque to see weights with each axle loaded to GAWR, and use that to go to the chart. Share this post Link to post Share on other sites
lazylizard2 Report post Posted January 27, 2020 Thank you I'll try that, I guess I would find that info on the driver's side placard I'm reading front 3175 (7000) and rear 5443 (12000) Share this post Link to post Share on other sites
richard5933 Report post Posted January 27, 2020 Lots of shops have a 'standard' pressure they use to fill newly installed tires. It's always a good idea to confirm the pressure they set is the proper one for your particular coach using the load and inflation tables. Like Brett said, if you don't have actual weight go with the placard until you get the coach weighed. Share this post Link to post Share on other sites
lazylizard2 Report post Posted January 27, 2020 Thank you Share this post Link to post Share on other sites
wolfe10 Report post Posted January 27, 2020 Yup, not reasonable to expect a dealer to know the correct PSI for your tires. How is he to know the actual weight-- whether you full time and have a rock collection or only lightly load for an occasional weekend trip. They SHOULD err on the side of too much PSI-- that gives a rough ride, but will do less damage to the tire than being under-inflated. It is an owner's job to take it from there. Share this post Link to post Share on other sites
lazylizard2 Report post Posted January 27, 2020 Spoke with rep from Michelin, who told me I need the axle weight of all four corners to determine psi. So should I divide the GAWR that i have on placard, in half for now until I get rig weighed Share this post Link to post Share on other sites
wolfe10 Report post Posted January 27, 2020 Ideal is to do "all wheel position weighing, then use heavier wheel position on each axle to determine the minimum PSI for all tires on that axle. Second best is to weigh the axles (most trucks stops), but that ASSUMES perfect left/right weight distribution-- not likely in a motorhome. So you would have to add more of a "fudge factor" to account for this. Third best is to go with the weights shown on your GVWR plaque, but that ASSUMES that you are not well under or over loaded compared with those ratings. Wish there were a simple answer, but as you can see from the Michelin site, the correct PSI may be 75 or 120-- too much difference to just guess. Share this post Link to post Share on other sites
lazylizard2 Report post Posted January 27, 2020 Thank you for all youve done. I'll do what you stated. Share this post Link to post Share on other sites
tireman9 Report post Posted January 28, 2020 You can follow Brett's advice right away. Then you can learn the How and Why of getting your proper inflation by reading my blog.www.RVTireSafety.net. Share this post Link to post Share on other sites
