Don't laugh fairly new with owning my first car and i wanted new rims for the coupe.

Need some explaination on the size. I know 18inch and 19 inch but explain what is the 9,5 or 10.5 and the offset measurments. which is related to the lip size?

Thanks for your help

 

For example, a 18x8.5 rim means an 18" diameter rim, that is 8.5" wide. The offset number represents the location of the mounting face within the width of the rim. So a zero offset would mean the mounting face is in the center of the rim [or from my example, 4.25" from the edge].

The required offset number [for proper fitment to avoid interference] varies from vehicle to vehicle. I don't know what the G coupe offset requirements are.