First, a little history. In 1975, the federal government created the Corporate Average Fuel Economy target (CAFE), which outlined a matrix of target fuel economy standards as standards for cars and light trucks. The system raised the average fuel economy of cars from 18 to 27 (so, in broad terms, 10 MPG over 30 years). Trucks, as you may know, are classified separately, a fact which helped in no small part drive the boom in SUVs over the past decade.
And now, there's new talk about increasing the CAFE standards, which I'm all in favor of. But in light of our simultaneous need to reduce emissions, I think we need to consider a new standard.
We've invested a lot of effort in the CAFE system, despite its failings (its part in the SUV boom being chief among them). And we're in a situation where we're far behind where we should be - it's hard for me to understand how, for example, my parents' 1973 Capri and my wife's 2004 Pontiac seat the same number of people and get virtually identical mileage. The fact that modern cars are safer and therefore heavier than their predecessors is part of the explanation but not the whole answer.
At the same time, we've been implementing a patchwork of federal and state tailpipe emissions standards, largely addressing hydrocarbon, nitrogen oxide and carbon monoxide emissions. Greenhouse gas emissions aren't yet part of the equation (though this may change if the Obama administration gives states an EPA waiver to regulate automobile CO2 emissions).
But what if there's a third option not being considered here: Regulate automobile and truck economy on an emissions basis.
I don't have the numbers at my disposal, but the idea is something like this:
Today's car burns an indeterminate amount of fuel, and from this fuel emits a quantity of pollutants on a per-mile basis.
By regulating pollutants per mile rather than miles per gallon, it would create an incentive to both develop cleaner technologies and reduce the overall fuel consumption - because, after all, burning less fuel is the most direct and least expensive means to reduce emissions on a per-mile basis.
And it does something that moving the CAFE lever alone doesn't do: it puts the burden back in the laps of the automakers. It gives them a choice - if you can build the business case, go ahead and build the monstrous SUV, but you'll need to find a way to make it run cleanly, and that will drive up the retail price; on the other hand, if you want to build small, cheap, efficient cars, you'll be able to do so while controlling your development costs.
It's not a perfect solution, but perhaps another way to slice the problem. I'd be interested to hear what the kos mind collective has to say.