ok...so whats the deal with the two? Im getting some new rims...and im wondering what the diff is.....

Both terms mean the same thing.

Ok, so whats the stock offset for the stock SUBARU 13x5 suby rims? 40 something MM?

Actually Offset and Back space are 2 different things.

 

Here's a link with okay deffinations of both

 

http://customwheelsmarket.com/wheelter1.html

 

Are you looking for specs on EA81 or EA82 Wheels? There is a difference in the backspace and offset between them. This has to do with EA82 needing additional clearance around the brake caliper. Also the Stock sice for a GL is 13x6 some EA81 DLs got 13x5.5

If you have one loose (not on a car) just put something nice and flat over it and measure to the hub mounting surface. and what kind of wheels are you getting?

thanks GT.

 

JWX: I am looking for some 15x8's. Some 225/45/15 Hooiser's are going on them.

What GLCraigGT said.

 

Basically, offset is measured from the center of the wheel and backspace is from the inside of the wheel. Here's a good example for using wider wheels: If you go from a 6" wheel to a 8" wheel and keep the same offset, then the wheel extends 1" more on the strut side and 1" more on the fender side. But, if you do the same and keep the same backspace instead, then the whole 2" will be added to the fender side.

 

Most people, when upsizing wheel widths, tend to reduce offset (thus making the wheel stick out farther) as it's easier to change your fender for clearance than it is your strut...LOL

 

Also, as a rule, domestic applications tend to use back spacing more often (measured in inches) and import applications tend to use offset more often (measured in millimeters).

Coolness. THanks.