what is offset??

[420playboy328is]

I have an e36 bolt pattern 5x120, when i bought the car it already had lowering springs on it, dont know what kind, I am also running 16" stock sport rims on my 328is.......so if i want to upgrade to 18 or 19" rims what does offset have to do with it..? thanks in advance

[vrsixer]

You may want to post this into the Wheels/Tires section. Or even search in there for your question... might get a quicker answer :D

[Daved]

http://www.tirerack.com/wheels/tech/techpage.jsp?techid=101