Since my previous fill-up of the Prius, I've been trying to drive in a more efficient way. I've been using the following guidelines as I drive:
1. Drive in the slow lane.
2. Don't slam on the gas to accelerate.
3. Be not an aggressive driver.
The last time I checked my mileage, I was getting about 44 miles per gallon (the read-out in the car said 48. Today, when we filled up, I checked my mileage again. The on-board computer said that we were getting 53.7 miles per gallon, but the actual mileage was 50.7 (404.2 miles on 7.973 gallons of gas).
So, there you go. An increase of 6 miles per gallon just by driving smarter. You too can do it!