I came across this while on another site.
Article from: IntegraR0064 at SHO
So...what is offset anyway?
Your rim is basically a metal cylinder, with some spokes and a mounting surface inside the cylinder. The offset is the distance between the centerline of the wheel and the spokes/mounting surface. I could make you a picture, but it would be ugly and I like the one on the tire rack site (
www.tirerack.com)
So if you had a zero offset wheel, the spokes and mounting surface would be right in the center of the cylinder. You've probably noticed most cars have the mounting surface right near the outside edge of the cylinder though, and thats because most cars nowadays (and ALL hondas/acuras) have a positive offset. Moving the mounting surface towards the outside edge of the rim is a positive offset. Recessing it into the rim farther than the centerline is also seen sometimes on rear wheel drive cars, although rarely. Thats called a negative offset.
Hope this helps