basalt986

I'm trying to figure out the offset on some wheels I have. They're 996.362.124.01 7Jx17 & 996.326.128.01 9Jx17. There are other numbers printed on the wheel in various spots. Are any of these the offset? The one that sounds offset-ish is a 55 on the outside near the lip.
Or is there some list somewhere of offsets for each model number?

Thanks.

Grun_RS

I'm not sure about the later factory wheels, but on the older wheels the offset stamped next to the valve-stem. My 993 wheels are ET 55 [frt.] & ET 65 [Rr].