KC, this is probably too late for your departure schedule, but our coaches as you recall are similar though likely weight-loaded differently. That said, when new at BCS the Goodyear tires were 110psi all around. That made for a little “stiffer” ride than I liked. At the next year’s FMCA rally in Redmond we ran the coach through the RVSEF weight test program.
The RVSEF ultimately recommended 95psi on the front tires and 105psi on the rears, which I’ve run in them since. Remember that those figures are based on my axle loads as we normally load our coach. Your slightly longer rig likely balances and distributes weight a bit differently.
When Les Schwab put Toyo tires on in 2015, they filled to 110psi front and 100psi rear. That was somewhat different than RVSEF’s figures that put less air in the front than the rears. My take was Les Schwab was using standard procedures for Toyos and coaches of our type. The RVSEF numbers were more based on our specific coach and loading, so I still follow their guideline.
I think 100psi all around would suffice for either of our rigs, frankly. 5-10 lb variations from that may slightly affect ride or wear and handling, but not be particularly hazardous. Leaning toward 110 would be better than 95; just don’t go below 95. 110 in the front will handle better but ride stiffer and wear in the tire middle faster, 120 even more so and I wouldn’t go there on coaches of our size and region of travel; 95 in the front will ride nicer but not steer as easily and be more susceptible to heating and edge wear. I’d expect 100 to be a good compromise.
The best thing would be to get an RVSEF analysis whenever the opportunity affords itself, because it precisely considers how you distribute load in your own coach, and the specifics of the tire model you’ve mounted. Check their website for such potential opportunities.
https://www.rvsafety.com/scheduleIn the meantime you shouldn’t go wrong going with the numbers your Michelin dealer initially used when he mounted them. He should’ve provided those on your receipt, or you could call him.
Joel