Careful planning can save you a lot of fuel expense. My truck is a high top utility at 8 MPG. If I had a smaller truck I wouldn't be able to always have what I need, which would result in more miles driven. So in a way I am actually saving on fuel when you consider that.
I try to plan my calls, Northside one day, eastside the next etc. Also, think about charging extra for the farther out jobs.