Brake rotor question
 

I am trying to locate front rotors for my car and am having a little trouble. When I measure the rotors on the car they are 28mm thick by 315mm overall diameter. When rotor diameters are specified do they go by overall OD or the OD that the pads travels on the surface of the rotor?

The closest I can find is a 323mm x 30mm rotor on the newer A8s

Also my front brakes are the dual piston design.

Thanks

It's the brake rotor OD......
 

....here's the info from the Bently....

<img src="http://www.audipages.com/Tech_Articles/susp_whls_brake_steer/brakesize1.JPG">

It appears you have the 314 x 30 mm rotors.....I think that was standard for the 00's and later SWB that came with the dual piston rotors.

The 332 x 30 were for the A8L's if I'm not mistaken....

All the tools are at the performance center....if you have a hydraulic jack (I only have one right now) and some small jack stands (I have only tall ones that can be used in the rear right now), bring them over when we do the job....if you don't have them, no big deal....just an excuse to get them!

pw