I live in the Atlanta area, which means I have a sizable commute for my job. It wasn't originally that way. When we first moved here, we chose a house so close to my job that I could come home for lunch. However, the first position did not work out and I ended up taking a new position elsewhere.
In getting used to my commute, I noticed that the speed limit on Atlanta highways is 70 in most places; however, the sizable number of delays mean that you're doing 70 half the time and 20 the other half. When I started my new position, I was getting just under five round trips per tank. However, when the price of a gallon of gas surpassed $3.00, I finally decided to do something about it. I try to maintain my speed at no higher than 60 miles per hour. While I do get passed when the traffic is at full speed, I end up arriving at the next bottleneck probably only a minute later than everyone else. My trip takes only five minutes more at the lower speed. Now, though, I get over six round trips per tank as opposed to just under five.