My 2010 is 8 months old and finally past the 5k mile mark. With that said, my mileage has increased from 50 in the winter and before break-in to 70 mpg this summer almost immediately after break-in, and I think I've finally figured out how to drive this car without be too much of a traffic impediment. My last tank I actually calculated 61 mpg, the car's computer said 64; I am 200 miles into this tank and the computer sits at just under 70 mpg tonight and it has been floating between 69.0 and 70.5 mpg for the entire 200 miles. I won't know the hand calculated mpg for awhile but the computer numbers have me excited. If the battery was a bit larger i think I could do much better. I drive around on a drained battery nearly all the time, only a very short distance on the freeway everyday, the rest is secondary and tertiary roads. Sweet spot is 40 mph. I don't know what mods are out there yet, but i would be interested in doing something to hit 100 mpg for a reasonable cost.