This should help millions, gw champ .
alot of guys are kind of confused about the whole offset thing with positive and negative offset. hopefully this can help guys out from now on
The offset of a wheel is the distance from its hub mounting surface to the centerline of the wheel. The offset can be one of three types.
ZERO OFFSET
The hub mounting surface is even with the centerline of the wheel.
POSITIVE OFFSET
The hub mounting surface is toward the front or wheel side of the wheel. Positive offset wheels are generally found on front wheel drive cars and newer rear drive cars.
NEGATIVE OFFSET
The hub mounting surface is toward the back or brake side of the wheels centerline. "Deep dish" wheels are typically a negative offset.
MEASURING OFFSET
To determine the offset, the wheel must be measured accurately using the following steps:
1) measure the overall rim width of the wheel.
2) measure the backspace, which is the measurement from the hub surface contact area to the outside of the inner rim.
3) divide the overall rim width by 2 which gives you the center line.
4) subtract the center line (overall rim width divided by 2) from the backspace.
5) a negative answer means the wheel has a negative offset and a positive answer means the wheel has a positive offset
This should help millions, gw champ .
add that to the top post also...
also remember, dont measure from the outside of the lip to lip
its from the bead sealing edge to edge. people get caught out on that too
a couple of dumb question with i think easy answers .
1. how do ppl know by just looking at the wheels in a picture what offset the wheel are ?
2. how do you know what offset you need for you car >? all good to know how to work out the offset the wheel has .. but how do i apply it to actual fitting them on or getting it flushed with the guard without scraping anything in the inner gurads .
buy the wheels then get the car to fit around them....maximum win
Measuring from lip to lip will work fine when trying to find offsets. It's when you're trying to determine the wheel width that you should measure from where tyre would bead.
Some wheels come in certain widths and offsets. You can usually tell which ones they are comparing to guard clearance. It's when you have camber it gets a little tricky. Camber does a lot!
+1
J.
Try this website..Very handy