I have a Highlander Hybrid and have logged 1400 miles so far. I have found that the AC greatly decreases MPG around town. On the highway, you are better off with the AC on and the windows rolled up. I have been getting between 25.5 and 28.9 with combined mileage on the fillups so far. I think I still have a lot to learn about getting the best mileage from this SUV. Hang in there and your numbers will improve. The most difficult thing for me is to resist the urge to use all the power this car has.