Never saw a different offset in Alcoas or any other 22.5 wheel. You just turn them around. BUT they may only be polished on one side leading to the idea that they are different off sets.
My Phaeton came with 221/2" wheels when I bought it new but when it came time to change out the tires I changed the wheels to Alcoa's. I went with 4 polished and the 2 inter wheels I installed non polished. I don't think anything is wrong with using the steel wheels on the inside rear wheels but I wanted all aluminum. I took one of the steel wheels and put one of the used tires on and I am able to fit a fully mounted and aired up tire and wheel in the compartment next to my propane tank compartment. I sense changed the tires out again and then changed the spare to the newer aged out tires. I think I am old school but I feel better with a spare tire. I have extra steel wheels that I would gladly give to anyone who needs a spare for their motorhome. I live above Sacramento off highway 50.
Hikerdogs wrote: You might need new longer studs on the rear drums or rotors. Aluminum wheels are much thicker than steel ones.
On my coach the studs were long enough to accommodate one aluminum wheel per location but not two. Naturally, I chose to put the aluminum on the outside.
What I really wanted to do was go with supersingles but my coach uses low profile tires and I can't find any supersingles that diameter.
There was a guy on here a while back that converted his duals to supersingles and changed to lightweight drums. He reported significant weight savings but never posted anymore follow ups.