Tire pressures

[Lmcneil]

I have a 2005 Southwind 37c that had Goodyear G670 2.45/70 R 19.5 load range g. I replaced them with Michelins same size but load range h. They seem to ride much harsher with the same pressures 95 front and 85 rear. I am wondering if I should lower the pressures about 10 or 15 lbs for the heavier rated tires. The owners manual calls for the 95/85 but shows this with load range g.The Michelins are XZ2.

[mci7]

Owners manuals give pressures for best & softest ride, sure not best for the tire or tire wear. If you keep the pressures up close to the max listed, you & the tire will be happier, maybe a slightly bit rougher but happier.
Dave M

[J-Rooster]

IMHO, your going to have to experiment with tire pressures! My Michelin manual said 85 lbs. rear and 90 lbs. front. That did not work for me, rear tire squirm and the lower tire pressure that you use causes more tire heat and that's on Michelins website! I ended up going 100 psi all around and that is what worked for me after using different tire pressures!

[Lmcneil]

That's pretty much what I thought. All the dealers said the Michelins Should ride better, but apparently not. The coach turns a little squirrelly just like with overinflated tires. I'll try it for a short trip and see. Thanks for the info....

[Dale_Traveling]

Your owner's manual pressures are normally based on both the capacity of the axles and the original tire capacity, or in other words, as if you loaded to the maximum capacity of the coach (GVWR). The higher rated new tires will give a bit of a harder ride as the side walls are stiffer due to the increase capacity.

Without knowing your actual weights on the axles, or better still each wheel position, you're into unknown territory changing pressures especially reducing the pressure. Drop the pressure too much and you risk potential tire damage and worse yet a blow out. Get the coach weight checked with a full load (including passengers) that you normally take on a trip then cross reference the tire manufacture's chart for the recommended pressure for optimum tire performance and ride comfort. I don't think the ride will improve as much as you may like but it's worth a try.

[rgatijnet1]

The tire pressure is determined by the WEIGHT on your tires, NOT THE LOAD RATING. The higher load rating allows you to carry more weight, but ONLY if your wheels and axle are also rated for the higher load, BUT it does not change the air pressure for a set load. In other words, to carry a load of 3000 pounds, the correct air pressure will be exactly the same whether you have F, G, or H rated tires.

[wolfe10]

Go to Michelin's RV tire guide and look up the PSI for the tire/load you have on there now.