Is Buying a Hybrid Worse for Environment than Keeping Your Old Car?

[fritz schrichte]

I have heard personal finance experts (and my mother) tell me many times that buying a new car is often a bad financial decision. Now here's some evidence to show that it may also be a bad ecological decision. Before you rush out and buy a Prius, you may want to check the market for an old Geo Metro instead, says EcoGeek.org:

-Given that producing a car is an extremely energy and resource intensive endeavor, is it better for the environment to keep driving an old car, or to buy a new, more efficient one.

Unfortunately, that turns out to be a complicated question. In the end it depends on how long you'll keep driving your old car, how efficient it is, and what kind of car you're looking to upgrade to.

But to keep it simple, I'll be referencing a recent article from Salon's "Ask Pablo" series. A Toyota Prius produces about 1/4 of it's lifetime carbon emissions in the manufacturing process. The rest is produced by burning gasoline. That's about 113 million BTUs of energy. So, you have to make sure your old car is going to make up those 113 M BTUs when compared to the Prius. Coincidentally, burning 1000 gallons of gas is produces pretty much exactly 113 BTUs of energy.

So, you do the numbers with your own car. If switching to a Prius would save you more than 1,000 gallons of gas, then it'll be better for you to switch. If your car gets about 25 MPG (with a 20MPG difference between you and the Prius), then you're looking at 20,000 miles before it's environmentally better. For most, that's a few years of driving during which it's better to stick with your old car.

But it's always going to be greener to get an old car with roughly the same mileage as a Prius, like a Honda CRX or Geo Metro. But if you need the mileage and the comfort, the Prius is a good place to look.