We just bought my wife a 2009 Acadia SLE. We absolutely love the vehicle. We traded in her 2008 Toyota 4Runner because she complained about it on a daily basis (not enough room, rough ride, etc). I wanted to see if anyone else got poor gas mileage on the initial break in period. I did not even calculate the first tank. On the second tank, we did about half and half city versus highway mileage and we got around 14.5 MPG. I live in Louisiana where it is flat and we live in a small city where traffic is not that bad. I really thought it was going to get better gas mileage than that. The 4Runner was getting around 21 MPG on average in my area.