I just got a 2011 A4, one week ago. Three days ago I checked the oil level and the red bar was 3/4 the way down. Yesterday the bar was full to maximum. Anyone know what is going on withnthe oil sensor?

 

I assume you mean 3/4 full, instead of 3/4 the way down. Did you check your oil at different times - like the first time the car had warmed up and the second time it sat overnight? That would give a different reading.

Also, the Turbo eats oil in this thing, my stealership provides free fluid top offs at any time, I go about every 3k because it will be at 50%

 

It was 3/4 down meaning 1/4 from the bottom. I checked the oil through the MMI two days after I had taken delivery of the car. Then the line was solid red. A few days later it was only showing 1/4 red. Then it went back to solid red a day or so after that. When I took it to the dealership, the tech told me that the line represents one quart of oil, so when I checked it the second time it was registering that it was short 3/4 of a quart. They checked the oil level and it was fine, and since that it the line has been solid red.