Via Worldchanging:  Check out this handy gas savings calculator for hybrid vehicles.  It’s simple, but nifty—and good for minutes of uninterrupted fun!

The take home message—high-mileage hybrids can, in theory, save you a bundle.  But just how much money depends not only on how much gas costs, but also on how much driving you do, and what your other alternatives are.

  • So let’s say you expect to drive 2,000 miles per month, and that gas prices will stay at today’s level—in Washington state, roughly $2.21, as of this morning.  And let’s say you’re trying to decide whether to trade in your 15 mpg SUV for a Prius (56 mpg, on average).  In nominal dollars, you’ll spend $25,800 less on gas over 10 years if you buy the Prius—meaning that the gas savings alone would pay for the entire cost of the new hybrid.  The trade-in value of your SUV is just gravy.

    But, on the other hand, let’s say you drive only 500 miles a month, and you’re choosing between a new Prius and a used car that gets 30 miles per gallon.  In that case, the Prius only shaves about $2,000 off your 10-year gas bill: not nearly as good a deal.  A used car might be more economical.  And, as we’ve said before, if you’re willing to invest some of the cost difference between the Prius and the used car on other pollution control efforts, you can do quite a bit of good for the environment at the same time.

    Obviously, this is a fairly simple calculator.  It doesn’t factor in tax breaks for high-mileage vehicles, resale values of hybrids, or discounting of future spending on gas. But it certainly suggests that hybrids can pay for themselves over the long term—depending on how much you drive, and what your other options are.