Tire size for 2000 diesel 35' land yacht xc?

[dhshipley]

We have just bought a 2000 Airstream 35' diesel Land Yacht XC motorhome. It needs new tires! The rear ones are Michelin XRV 235/80 R22.5 and they are 10 years old and cracked. The front two are Dunlop 255/70 R22.5 and they are 7 years old. I cannot find in the manuals what size was suggested but I assume that since the rears were made in 1999 they are probably the ones that were installed on it when it came from the factory are the correct size to use. I wonder if there is a good reason someone put the different size on the front. Except for the difference in price. My tire dealer told me that Michelin is the only one that makes the 235/80 tires! I would appreciate some good information from someone who knows a lot more about this than I do!

DAVID & PEGGY SHIPLEY
MIDDLETOWN, OHIO
dhshipley@cinci.rr.com

[overlander63]

Wider front tires help steering and handling. 70 aspect ratio tires are wider than 80 aspect ratio. The number is a percentage of width to height.
If it were me, I'd get a set of 6 all of the same size, if for no other reason than if you have a flat front tire, you can swap it for a back one.
You could get a set of 245/75R22.5 tires, they'd fit with no problem.