Interesting article in Wired today entitled Go Green — Buy a Used Car. It’s Better Than a Hybrid. The basic idea is that there is a cost to producing a car, such as a Prius, that doesn’t get paid off in increased gas mileage for 46,000 miles. There is a callout to another Wired article, which states:
In 2006, an Oregon market research firm released an incendiary 500-page report. Its claim: A Humvee (13 miles per gallon city, 16 highway) uses less energy than a Prius (48 city, 45 highway). Scientists quickly debunked the study, but the Hummer lovers got one thing right. Pound for pound, making a Prius contributes more carbon to the atmosphere than making a Hummer, largely due to the environmental cost of the 30 pounds of nickel in the hybrid’s battery. Of course, the hybrid quickly erases that carbon deficit on the road, thanks to its vastly superior fuel economy.
Still, the comparison suggests a more sensible question. If a new Prius were placed head-to-head with a used car, would the Prius win? Don’t bet on it. Making a Prius consumes 113 million BTUs, according to sustainability engineer Pablo Päster. A single gallon of gas contains about 113,000 Btus, so Toyota’s green wonder guzzles the equivalent of 1,000 gallons before it clocks its first mile. A used car, on the other hand, starts with a significant advantage: The first owner has already paid off its carbon debt. Buy a decade-old Toyota Tercel, which gets a respectable 35 mpg, and the Prius will have to drive 100,000 miles to catch up.
It seems to me that this misses the point. I understand the argument that the first owner of used car is the one that pays off the carbon debt of manufacturing, so that the next owner starts with no debt to pay off. But what is the alternative? All cars have to be manufactured and have to have an original owner. Yes, one can think about how to decrease the carbon cost of manufacturing, and that is surely a worthy goal. But is seems to me that the real question is not how many owners a car has, but what its total carbon cost is over the life of the vehicle. It is highly likely that the carbon footprint of the Prius after 10 years will be less than that of the not quite as efficient Tercel. The planet doesn’t care if a car has 2 or 10 owners—the effect on the planet is still the same.
Don’t get me wrong. I think it is a great idea to buy a used car. The longer a car can stay on the road (provided it is running well and efficiently), the better it is for everyone. All I’m saying is that the unit of cost is the car, not the owner. To paraphrase James Carville: “It’s the car, stupid.”