I currently have 22 inch rims with 305/45/22 tires. The rims have an offset of +22 and a 6.02 backspace.

I am looking at buying 20 inch rims with 305/55/20 tires. The rims have an offset of +18 and a 5.75 backspace.

How far out will the 20s set compared to the 22s? I have factory fenders flares and want the tire to be flush with the flare. Right now the 22s set in about a 1/2 inch from the top of the fender flare.

Would I be better off buying new tires for my 22 inch rims instead of buying 20 inch rims and new tires? If so, what is the biggest 22 inch tire I could buy that would stick out more?

Thanks,
Dan