I want some new rims and am looking over at Jegs where I got my steel rims I have now, i want to go to some lighter alloy....

I have 8x15 rims on now w/ 3-3/4" back spacing...

Anywho, the ones i want at Jegs list "offset -27mm" for the ones i want......is that the same, 'cause 27mm is only 1.06"??

 Is offset a different measurment or the same thing as backspacing?

ok i have to answer this one. offset and back side setting are the same thing. the postion of the mounting pad in relation to the center of the wheel determines both. if you have a 0 offest that means the mounting pad is in the middle like on a 8 wide it would be zero offset 4 inch backside setting. the more negtive offset the more the mounting pad is moved inboard the decreases the backside setting the more postive the more the pad moves outboard the the backside setting goes up. a postive wheel is considered a fwd wheel and usally has a 5 plus back side setting on a 7 wide.

Yep, he is right.  The two aren't the SAME, but they do measure the same thing, from a different point.

Offset measures from the centerline of the wheel, Backspacing measures from the inside rim.

 Backspacing is the distance from the mounting surface to the furthest inboard point on the wheel (the inside rim) if you put a straight edge across the inner rim of the wheel, and measure in to the mounting surface, you get back space.. usually between 2 and 4 inches for rear wheel drive and 4x4 wheels

Offset is the distance  from the center of the wheel to the mounting surface and is either negative or positive, positive is toward the outside of the wheel, negative is towards the inside. This is used more in automotive alloy wheels, custom wheels, you know, bling.

0 offset, the mounting surface is in the center of the wheel

+27mm, the mounting surface is 27mm "offset" towards the outside of the wheel

-27mm is offest that much to the inside of the wheel.

SO, if you know the width of the wheel, and either the offset, OR backspacing, you can figure out the other dimension.

ie:  on an 8 inch rim, a -27mm offset would be a 3 inch backspacing, or would "stick out" 3/4" further than your current wheel.


Beware, some silly ass wheel sellers interchange offset for backspacing... BUT, it is usually pretty obvious in the measurements..


I know this is what Suzuki1.8 said, in different words.... I am agreeing.. (lol... it takes me a lot of words to agree...)