Hello every one, here is the lowdown and I google and didn't find anything. I took the car to the dealer and have them change the oil, they also asked to change the brake fluid and engine coolant, plus I paid an extra $50 for zMAX Micro-lubricant for the engine, hoping that actually going to drop the MPG as I did before worked, went from 21.5 to 22. I went back to the dealership, they said well ist AC I said I used the AC before we are in August, then they said they have to reset the MPG calculator which they did, and I told them, "you don't get it, I don't go by the computer calculation, I go by milage for full tank, I was getting 320-330 now I'm getting 250 and I went through three tanks since oil change. Can anyone possibly know what BMW technicians cant know??