DennisM

The best way to find out if 10k mile intervals are too long for you is to do a used oil analysis. No sense in guessing or listening to someone else's opinion.

http://www.blackstone-labs.com/

http://oaitesting.com/

http://www.wearcheck.com/

OHChris

It has been a while since I have been on the boards, but the Q5 has been great during the first year! I wanted to comment on a couple of recent replies. One person mentioned that the moisture and blowby gases take the place of the oil making it seem more full than it really is. Unless you are only driving 3-5 miles at a time, the oil heats up more than sufficiently to evaporate any water in the oil!
What DennisM said about running used oil analysis is true, the only thing that you need to watch out for is making conclusions based on one data point. You really need some history to see what is normal and what is abnormal. After running analysis after a few drains you can start to see patterns. Great discussion!