I frequently make a 100-mile-one-way trip to my second home in the mountains of Utah. There's almost a 2000-foot difference in elevation. This results in different mileage depending on which way I'm going. I became concerned that I wasn't getting the kind of mileage I was getting a year or so ago when I first got the car. I thought maybe there was something wrong with it. Coming back and losing elevation I would get in the high 80's mpg back then. Now it was down in the 60's. Then I realized that I had slowly began driving like a maniac. 80+ miles per hour on the freeway. Jack-rabbit starts. Yes, you can do that in a Volt. Everyone is driving faster because gas is so cheap. Also I suspect that driving in 'L' affects your mpg's. So lately I've tried driving 70 or under and driving in 'D' instead of 'L'. I set the cruise control at 70 and let people zoom past. Today my mileage was 83 mpg. It took a little over a gallon of gas. That's in the ballpark. I think I used to drive 65.