Since getting my A6 3.0 (quattro) AT used last year as a CPO, I have been periodically sucking and replacing the fluid in the resevoir with 11s using a turkey baster. The fluid was originally practically black, and 2 weeks ago was about medium dark green (the 11s is a nice lighter green color)...well low and behold, the pump started to moan and groan and the steering began to shimmy. I could feel it on cold days after 15 min rides, and it got progressively worse. Fortunately, I have the 100,000 mi plan, so I brought it to Audi and they replaced the pump. Took 1.5 hrs and cost me only 50 bux. I just opened the resevoir and the fluid is now almost clear with a slight pale green tinge. I suspect that they use 7.1 fluid.
Time to throw the 11s in the garbage.
do what you want but I will no longer be changing this fluid and certainly if it needs topping off, i will follow the advice printed on the resevoir plastic which says use only mineral based oil.