Changed tire size on motor home

[fitzjohnfan]

So a couple of months ago, we upgraded and purchased a 2003 National Dolphin on the Workhorse W22 chassis. The original tires on it were Michelin XZE 235/80 R22.5 tires, but they were over 14 years old on the date codes. Before driving it from Salt Lake back home to Denver, I insisted we get new tires, and the dealership was able to get me a "deal" on 6 new tires from a local shop. This new size is 275/70 R22.5

These are AR602 PrinX tires. I know,no name, but they ride nice and seem to handle well.

Just wondering if I will encounter problems with the tire size change? Also, these tires don't have any inflation tables in relation to the vehicle weight, so should I just go by the recommended psi on the coach sticker?

Thanks,
Chris g.

[CamJam1]

Your dealer steered you to the wrong size, though I doubt it will cause you any problems. 235/80E22.5 is a Michelin only size. It has a diameter of 37.1 inches. The accepted replacement size is 245/75R22.5, which is 37 inches diameter. What you got are 37.66 inches, so at a minimum your speedometer will read a little low. More importantly, the W-22 in 2003 came with 6.75" wide steel wheels, and your 275/70 tires are likely designed for a minimum wheel width of 7.5". If you have aluminum wheels there's a chance they could be wider, but the steel wheels were only 6.75" in 2003. Is this a problem? Probably not, provided your rear duals don't touch. Your tires may wear more in the center from behind squished onto the narrower rim, but moho tires usually age out long before they wear out.

What's the load range on the new tires? They came from the factory with G. Anything more than that will likely stiffin the ride.

[fitzjohnfan]

Originally Posted by CamJam1

Your dealer steered you to the wrong size, though I doubt it will cause you any problems. 235/80E22.5 is a Michelin only size. It has a diameter of 37.1 inches. The accepted replacement size is 245/75R22.5, which is 37 inches diameter. What you got are 37.66 inches, so at a minimum your speedometer will read a little low. More importantly, the W-22 in 2003 came with 6.75" wide steel wheels, and your 275/70 tires are likely designed for a minimum wheel width of 7.5". If you have aluminum wheels there's a chance they could be wider, but the steel wheels were only 6.75" in 2003. Is this a problem? Probably not, provided your rear duals don't touch. Your tires may wear more in the center from behind squished onto the narrower rim, but moho tires usually age out long before they wear out.

What's the load range on the new tires? They came from the factory with G. Anything more than that will likely stiffin the ride.

Thanks for the reply. They are load range J and I also verified that the duals are not even close to touching, so I guess that's good.

[CamJam1]

Must have been tired when I wrote that. It's spelled "stiffen".