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# Which vehicle upgrade saves the most energy?

This question is from the interactive quiz "What saves more energy?" on Money.CNN.com.

Which vehicle upgrade saves the most energy?
A) Switching from a 16mpg SUV to a 20mpg SUV.
B) Switching from a 35mpg car to a 50mpg car.

After you select your choice, CNN explains the answer. Can you see the mistake in their calculation of gallons used over 10,000 miles of driving.
Note: There are other ways to save fuel. Suggest some.
Note: Some European car reviews use L/100km. Is that more intuitive than mpg or km/liter?

Views: 33

### Replies to This Discussion

Interesting. My 'hurried' calculation resulted in a savings of only 85.7 gallons over 10,000 for the car upgrade rather than 94. Correct me if I"m off. Even though you "save" more upgrading the gas guzzlers they are still using more than twice as much gas as the cars.......I just got back from a nice hour long bike ride. No gas. That works!
The original paper (search for Attari and Energy), on which the CNN Energy quiz is based, is here as free PDF download: http://www.pnas.org/content/early/2010/08/06/1001509107.full.pdf+html
Shahzeen Attari, the author of that paper, is participating in the discussion "What do you think of this quiz on CNN.com from a mathematics or education perspective?" on the "Math, Math Education, Math Culture" group on LinkedIn.com.