[graydonengineering]

Nice! Yes, the wind is a real killer as are slight inclines that you may not even notice. If you have done much bike riding, you know that to be true but without a gauge, it is near impossable to keep tabs on while driving. My experience has shown windows down has minimal impact but AC can take me down a ton. For example, engine on coasing without ac is about 100 mpg but with ac is about 75. Thants 25% in that case! 45 mph constant without AC is about 35mpg, with AC is about 27. Under major load, the AC hit is not enough to tell really. My best tank before my SG2 was 25mpg, my current best is near 31! You have to know what your car is doing to respond for best mpg. It's a big investment but it will pay for it's self.