I have a 2002 Audi A6 2.7T with Tip., i was wondering what size rotors i have since there is two different sizes 315mmand maybe 321mm, having to buy pads and it came up with 2 different types. Thanks for the help. And how can you tell also. Instead of having to take off the rim.

 

Your rotors are321mm. As for pads you might have to check...most 2002 2.7T'shave 4 pad HP2 calipers,but I have heard of some out there with 2 pad ATE calipers.