If my commute was only 2.5 miles one way, I would be driving the biggest dirtiest most fuel inefficient trucks on the face of the earth. And it would not be that bad because 5 miles a day is almost no vehicle usage at all.

If I had a commute that short, there is no way I would have ever thought about getting a hybrid. The payback for the better fuel economy would take way too long. I got mine because I commute 58 miles one way. With that I get between 35-40 MPG.

About the only thing you could add to your commute to get worse mileage is a stiff head wind. I got one of my worst tank averages this weekend. I was driving 75 - 80 MPH into a 20 - 30 MPH head wind, and I averaged 35 MPG on the tank. I don't think that is too bad considering the conditions.

The only thing I think is funny, is people are telling you to drive more to get better mileage, but driving more burns more fuel, which is exactly what you don't want to do. Taking a trip that is wanted is one thing, but driving to just get your average up is silly.