Fuel economy in cars is going up. The 2025 CAFÉ standard for cars is over 54 miles per gallon. Hybrids and plug-in vehicles reduce the amount of energy we use to drive, and we all should want to lower our energy consumption and our carbon footprint. But does buying a high-mileage car really help?
To answer that question we need to not only know how much energy it takes to drive the car; we need to know how much energy it takes to build the car. Several years ago, Argonne National Laboratory explored this issue in detail and came up with the numbers.
The result? It requires lots of energy to mine, manufacture, and move around the parts that go into a modern car. On the average, it takes over 31,000 BTUs to produce every pound of a new car. For a 3,200-pound car, that adds up to 100 million BTUs. Put in terms we can actually understand, that’s the energy contained in about 800 gallons of gasoline.
For most of us, we could drive for a year or two on 800 gallons of gasoline. So it would take a long time to save energy by buying a new, high-mileage car.
Buying a new car to save money is equally problematic. In terms of money and energy, it generally pays to drive the same car as long as possible.
There are many good reasons to get a new car and, sooner or later, we all will. The good news is that once they are built, a wide variety of new cars are using less energy.
Web Links
Development and Applications of GREET 2.7 (Argonne National Laboratory)
http://www.transportation.anl.gov/pdfs/TA/378.PDF.
Photo, taken in 2011, courtesy of Stuart Axe via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY, with partial support from the Field Day Foundation.