My own take on CAFE standards is roughly Kevin Drum's: There's no need to think of CAFE standards and gas taxes as an either/or choice. And you can probably get more done with both than with either alone.
In fact, there's reason to believe that gas taxes wouldn't raise efficiency as effectively as CAFE standards. Consumers typically undervalue the benefits of fuel efficiency -- they only take a few years worth of gas savings into account when buying a car, even if they plan on holding onto the car for much longer. That's not necessarily rational, but it's apparently human (or at least American) nature. And it means that fuel taxes probably would need to be really steep to get the same result as CAFE standards.
Now, as long as we're dreaming about conservation policy, there are two ideas that get much less attention than either gas taxes or CAFE standards, but that could be far more effective than either.
