Quick: which saves more fuel? Boosting miles per gallon from 10 to 11? Or from 33 to 50?
Neither. They both save the same amount—one gallon of gasoline every 100 miles. And that's why some behavioral scientists think gallons per mile is a better metric. Because it tells you exactly how much fuel your car will burn per mile traveled. As a result, the U.S. Environmental Protection Agency added gallons per 100 miles to fuel economy labels in 2013.
Now new research suggests that's not the only way to better inform new car buyers of the fuel efficiency of their vehicle.
To test what works best, management researchers at Duke University's business school offered would-be car buyers a host of labeling options in an experiment. The labels ranged from gallons of gas used per 100 miles to cost of gas over 100,000 miles.
When consumers saw that cost-of-gas label, they picked the most fuel efficient car every time. The research appeared in the Journal of Public Policy & Marketing. [Adrian R. Camilleri and Richard P. Larrick, Metric and Scale Design as Choice Architecture Tools]
The finding suggests that cost is the main driver for people to opt for fuel efficiency. And if lifetime fuel cost is what matters, maybe that ought to be on the new car labels, too.
[The above text is a transcript of this podcast.]