Originally Posted by mbeach
O.K., you have to follow along here.
Joe Black is running 15x7 wheels with an offset of +40mm.
About 2mm of the inside edge of the rim contacted the upper control arms. So...
These wheels (15x7) equal an offset of 5.07".
Therefore, we can safely assume (?) that the upper control arm lies 5.00" inboard of the mounting pad for the wheel. (that 2mm of contact = 0.08").
Still following me...?
You need to find the correct backspacing for an 8" wide wheel.
Well, 1/2 of your rim width = 4.0" If you find a wheel with 4.0" of backspacing, it WILL NOT hit your upper control arms BUT , it will cause problems with the rubbing of fenders and such -many members have had troubles with +0 wheels.
So...
You need to split the difference. Not too much rim inside, and not too much rim outside.
Somewhere between a backspacing of 4 and 5 inches will be best. I'd get as close to 5" as possible, without actually hitting 5". This will keep the wheels tucked in, fighting the dreaded rub AND it will keep the wheels out far enough that your small diameter rims won't rub your suspension bits.
Make sense..?
Go for the 4.75" wheels.
This is the same as a 15x8 wheel with a +20mm offset. This has been proven to fit the VX as long as you don't get too crazy with the tire selection.