Can anyone tell me the difference between a 17x8.5 with 0 offset 4.5" back spacing and 17x9 with 0 offset 5" backspacing? Will the 17x8.5 be tucked in more than the 17x9? I am so bad at this wheel stuff.

 

Are both advertised that way? For a rough calc, a rim is actually about 1" wider than what its advertised. So a 17x9 is actually 10" wide, and 0 offset means the mount face is flush with the wheel centerline (so 5" behind it, 5" in front of it). I imagine a 8.5" with 0 offset would be 4.75" backspacing (and frontspacing).


But the difference in any wheel with identical offsets and different widths, take the width, divide by 2, and you have that much more sticking out the outside, and the inside.

Basically, center of wheel stays in place, both inside/outside get wider equally.