This is good advice. I will keep it to 5-6k.

My Denali has a fancy system that illuminates dash light when it's ready for an oil change. It has some system that analyzes the oil every x amount of crankshaft rotations. Pretty nifty. Generally, it illuminates between 5k-7k but it went 8500 once and as early as 2100 when I drove it to Las Vegas and around in 115 degree heat for a week. You never REALLY know when your car needs an oil change so I suppose that is why it is important to play it safe. I just wish more cars had this system in it!

 

The 08 dont have free maintenance anymore and yet the factory recommanded oil change interval is still 10K miles. You would think if anything, Audi would lower that interval so the dealer can make more money.

 

Jeff really does seem pretty smart from all of his posts that ive read but I really dont see much harm in running 7k with the 4.2. I mean, it has a very easy life in the A6. I understand 5K on my 2.8, it has to work hard. My oil temp is always 225*, sometimes higher if my foots in it hard. Ive never seen our 4.2 touaregs oil temp go above 200*, even when towing boats. Im not sure if its the same case with the A6 but that motor does not have to work hard. Ours has 6k on this change, and its still gold, hard to see on the stick. My 2.8 is pretty brown by 5k.
My car tells me 10k oil changes, the service oil thing comes on every other time I change my oil. Imo, that is too far on one change but I think 7-7.5k would still be fine on a 4.2.