Our total distance travelled was lower this year, mostly because our longest driving trip was taken in a rental car. The fuel economy was quite a bit lower, probably because the longer trip we did take was in the mountains of colorado, and a long climbing drive can be pretty awful for efficiency. The car also had its tires replaced this year, and the new tires may not reach the same level of low rolling resistance. Finally, it might be the case that an aging traction battery is affecting performance. Frankly, I'm disappointed with the numbers for the year.