The Daily Grist picks up on a forthcoming study that says heavier people use more gas:
Here's more motivation to go on that diet: You'll use less gasoline. Non-commercial U.S. vehicles are using at least 938 million more gallons of gasoline annually than they did in 1960 because drivers and passengers are considerably heavier and are dragging down fuel economy, says a University of Illinois study to be published in The Engineering Economist. In 1960, the average adult female weighed 140 pounds and the average male weighed 166; in 2002, the averages were 164 and 191 respectively, and 62 percent of adults were considered overweight. That 938 million gallons is no shabby amount: It represents $2.8 billion if gas is selling for $3 a gallon, and could fuel some 1.7 million cars for a year, or feed the entire U.S. gasoline addiction for three days. "We had no idea the numbers would be this big," said study coauthor Sheldon Jacobson, who calls using less fuel an "unexpected benefit" of losing that spare tire.
I'm not saying that I don't believe it, but ...
The Daily Grist picked up the story from the LATimes, among other newspapers. The LATimes story finishes up with this:
Any savings would be insignificant, said John Felmy, chief economist for the American Petroleum Institute.
"It's an interesting calculation," Felmy said. "But we use about 140 billion gallons a year. The savings would be less than 1%."
A representative of the Automobile Club of Southern California, which has long preached that changes in driving habits can dramatically reduce gasoline consumption, said the human weight factor is far overshadowed by others.
Let's say that a typical new car sold these days weighs about 4000 pounds. A 50 pound increase (one heavier male, one heavier female) is a 1.25 % increase in total weight. If the gasoline savings are about 1%, the elasticity of gas to weight (% change in gasoline divided by the % change in weight) is 0.80.
Hmmm. Maybe the estimate ain't so crazy.
Extrapolating, if the typical car turns into a typical car sold 25 years ago (3200 pounds), a 20% decrease in weight, then fuel consumption would fall by 16%, or 22 billion gallons. At $2.50 per gallon, that is an $56 billion decrease in gas consumption (assuming no behavioral change as cars get smaller). The average household would save almost $1900.
The moral of the story? If you want to save money, don't bother losing 25 pounds. Instead, buy a smaller car and squeeze your-heavy-self in.
