Rex wrote:
Forgive me if I'm off in left field, but I'm not aware of any way a wheel can be the same width and offset, yet have a different size lip as you're describing??
Also, OP be cautious as 245/45 in a 20" tire would be much taller, then his 18's.
I don't see why this is a difficult concept to understand... if you truly understand the definition of offsets..
the center of the wheel is the center of the wheel.... that doesn't change...
if the offset is merely the point at which the hub mounts as related to the center of the wheel, that can easily stay the same, on the same width wheel, while changing lip sizes...you just vary the point of attachment of the spokes to the wheel... Spoke attachment to the base of the wheel has NOTHING to do with determining wheel offset!
also, I've never met anybody running 225/35/20's... it could be done, but why put so little rubber on the road? the 245/35/20's that everyone runs not only puts +20 mm more rubber on the road, but the sidewalls are thicker also, providing a more comfortable ride!