Today was I able to make another small improvement. I replaced my 03 Ford F-150 pickup with a Subaru Impreza. Here's how the improvement breaks down:
Financial benefit: I'm replacing a 5 year old vehicle that I own which costs me pay 375/month on the loan with a new leased vehicle that will cost be about 300/month (lease). I can expect to save approx 15 percent on gas since the Impreza has better mileage. ( 20/27 vs. 17/20 ) and another $75 per month for the duration of the lease.
Environmental benefit: the Impreza gets about 20/27mpg while the pickup got about 17/20 mpg. That's roughly a 15 percent improvement. So far I have been able to get 27 to 31 mpg by applying simple "hypermiling" techniques. The acutal saving when adding hypermiling to the equation, and factoring in my old inefficient driving techniques may actually result in a 30 to 50 % improvement. ( Given the way I drove before I was probably not getting a full 17/20mpg )
Economic benefit: By using less gas, less hard earned domestic currency is getting sent off to foreign countries ( like Saudi Arabia ). Also using less gas lowers the demand for oil which in turn lowers the price of oil.