EarthTalk: When is it best to buy a more fuel-efficient car?
Newer models may save fuel, but consider the carbon footprint involved in manufacturing them.
Melanie Stetson Freeman/Staff
Q: Is it better to drive an older, well-maintained car that gets about 25 miles per gallon or to buy a new car that gets about 35 miles per gallon?
– Edward Peabody, via e-mail
A: It definitely makes more sense from a green perspective to keep your old car running and well-maintained as long as you can – especially if it’s getting such good mileage. There are significant environmental costs to both manufacturing a new automobile and adding your old car to the ever-growing collective junk heap.
A 2004 analysis by Toyota found that as much as 28 percent of the carbon dioxide emissions generated during the life cycle of a typical gasoline-powered car can occur during its manufacture and transportation to the dealer; the remaining emissions occur during driving once its new owner takes possession.
Regardless of which result is closer to the truth, your current car has already passed its manufacture and transport stage, so the relevant comparison has to do with its remaining carbon footprint compared with that of a new car’s manufacture, transport, and driver’s footprints – not to mention the environmental impact of disposing of your old car or selling it to a new owner who will continue to drive it. There are environmental impacts even if your old car is junked, dismantled, and sold for parts and scrap.
Don’t forget that the new hybrids – despite their lower emissions and better gas mileage – actually have a much larger environmental impact in their manufacturing compared with nonhybrids.