Where on the car or how do I find this out? Thanks

Where on the car or how do I find this out? Thanks
Location of RPO codes depend on your model year. You didn't say!

Or, crawl under the rearend and look at the tag on your differential.

:cheers:

Here's some for 99

G92 Performance Axle Ratio 3.15:1 MXO Auto
GU2 Std. Axle Ratio 2.73:1 MXO Auto
GU6 Std. Axle Ratio 3.42:1 Six Speed

or drive the car and see what RPM you are at when you are doing 55 mph. then we can look it up.

:cheers:

Where on the car or how do I find this out? Thanks

Drive 75 mph in 3rd on A4s and 4th on M6 and M12 divide rpm by 1000.
Assumes stock tire heights

or drive the car and see what RPM you are at when you are doing 55 mph. then we can look it up.

:cheers:

You can really tell buy this? LOL I'm going to make a point of righting this down! :)