A maxim in business says that you get what you measure. If that’s true, then the way we measure things becomes crucially important (which will hardly surprise Molluscovites, I’m sure), like, say, fuel efficiency. A recently published study from Duke University highlights the fallacy of mpg. Instead of measuring the number of miles we get per gallon, we should measure the number of gallons we need to travel a set distance. When you work out the numbers, you get some unexpected results. I considered the two upgrades proposed in the paper: From an SUV to a station wagon, and from an econobox to a hybrid. I used what my auto insurer considers a normal year of driving, 12,000 miles, and a fuel price of $4.50 per gallon.
|Make and Model||Mileage||Gallons per 12,000 miles||Savings from upgrade at $4.50 per gallon|
|Dodge Durango||15 mpg||800 gallons|
Even though the upgrade from the SUV to the wagon only improves mileage by 10 mpg, it actually saves 320 gallons of fuel. Despite a 20 mpg improvement, the upgrade from the Civic to the Prius saves only 160 gallons per year.
The point of this analysis is not to say we shouldn’t all be driving high fuel efficiency cars, because we should, but it is to say that it’s far more important to get all those behemoths off the road than it is for all us latte-drinking, tree-hugging liberals to swap our Civic for hybrids, no matter how much we really, really want to. Getting SUV drivers into hybrid SUVs or smaller wagons will make a far bigger difference to the good earth. Which is why, even though I think it’s criminal that the price for raising CAFE standards was the jettisoning of tax breaks for solar power and wind power, Congress actually did something pretty meaningful. Raising the minimum mileage will have the heaviest impact on the worst offenders.
I also liked this new way of measuring because it finally explains why I’m having trouble calculating at what price of gas will the added cost of a new hybrid break even with a new Civic. I keep getting numbers that seem too high ($7 a gallon, or even $8, depending on which assumptions I use. I hope to have a whole post on this in the future). Now I see why: the marginal improvement of the Prius from the Civic just isn’t that great, at least not at today’s prices. Over the course of 10 years, the savings would be worth $7,200. But if I had a Durango (which I don’t!), and I went to the Toyota Wagon, I’d save $14,400 at today’s gas prices.
Of course fuel efficiency isn’t everything. Slate’s Green Lantern column just did an excellent cradle-to-grave analysis of the energy costs of buying a used Civic versus buying a new Prius and figured out that it was still more energy efficient to buy the new Prius. Now if I can just find that $21,500 I buried out in the yard for a special occasion…