What is "offset"

[Hoosier_300C]

I've read a lot on here about rims and keep seeing "offset" brought up for 20" and 22".

I think I've finally made up my mind that I'm going to stick with 20" for my car. I found a set I like made by Foose (Foose Speedster in Black). They are available in 20x8.5 and 20x9.5

Obviously the 9.5 is going to have the benefit of more rubber on the road, and I'm planning on going back to the stock 18's from November through March (midwest winters....blech).

So what is "offset" and how can I tell what the offset of these rims are, and what does it do.

Sorry for the st00pid n00b questions, but I'm really unfamiliar with car customizations, as my 300C will be my first customized car, I'm trying to learn as much as I can so I don't mess anything up and flush 40K down the drain....lol.

[Jerry M.]

I was curious about the same thing, I found this web site. See if this helps.
http://www.usacomp.com/Offset.htm

[mmmmm127]

Originally Posted by Hoosier_300C

So what is "offset" and how can I tell what the offset of these rims are, and what does it do.

The offset is the actual distance in mm between the plane through the point of attachment of the rim to the car and the plane down the actual centre of the rim. It can be a positve or negative value. Offset determines the vehicle/tyre "fit" and for the AWD is plus 55 mm, therefore 2 vertical (sagital) planes lie 55 mm apart. The value is much less for the RW drive cars. You choose your tyre/rim combo on personal preference, you choose the ofset on the car's needs....

[Hoosier_300C]

Cool, thanks. I just E-mailed the sales rep for All Star Rims to see what the offset of the 20" Foose Speedster B in 8.5 and 9.5 widths are. I'll post the reply when I get it.

[Hoosier_300C]

Wow...that was fast, here is the reply:



Hello I can get you a front offset of 18-22 and a rear of 15-27 they are both available.

Thank you,
Sevan Karayan

Sevan@Allstarrims.com



So from this note, and compared with what is written in the tech forum about 20" rims, these should work in either 8.5 or 9.5 widths, shouldn't they?




Wow, I'm gettin' smarter every day.

[II kings 9:20]

How does one decide what offset to pick, is this done in the wheel or with spacers.

[Hoosier_300C]

Originally Posted by II kings 9:20

How does one decide what offset to pick, is this done in the wheel or with spacers.

UPDATE:

Here is the latest note I got in response to Offset from the sales manager at All Star Rims:

Hello we will send you the right wheel when you place the order in regards to back spacing and bolt pattern.Thank you,
Sevan Karayan

Sevan@Allstarrims.com



So I'm guessing they have a database of what cars require what offset and bolt pattern?