This chart shows that in 1975, when the fuel crunch hit, new cars in the United States averaged 136 horsepower. The average declined to a low of 99 horsepower in 1982, as manufacturers scurried to raise fuel economy. (Higher horsepower means more gasoline burned.) Really, 99 horsepower isn't enough for anything larger than a minicar; you need enough horses to be able to accelerate, especially at freeway merge lanes. But in the last two decades, average horsepower has been climbing steadily. In 2004, the typical new car had 184 horsepower, and the typical new SUV or pickup truck used as a car--SUVs and pickups used as cars now account for about half of new vehicle sales--had 235 horsepower. That rolls together for an average of about 210 horsepower in new passenger vehicles sold in the United States. In other words 2004 cars, SUVs, and pickup trucks offer more than 50 percent better horsepower than passenger vehicles in 1975. (At that time there were no SUVs, and using a pickup truck as a car, rather than for commercial work, was rare.)
Ever-higher horsepower is the reason the overall fuel economy of new U.S. vehicles is now at its lowest since 1988. Engineers have steadily made automotive power trains more efficient--but nearly all the efficiency has gone into power, not MPG. Other things being equal, a one-third reduction in the horsepower of new vehicles would lead to roughly a one-third increase in their miles-per-gallon numbers. And a one-third increase in the MPG of new cars and SUVs is all that is required to eliminate petroleum imports from Persian Gulf states!
Now, I recognize I am past the age of caring very much about muscle cars (that is unless someone wants to indulge me in my fantasy of taking a HemiCuda out for a day on the Salt Flats.) But if Easterbrook is right, and we could be energy independent by merely chopping HP by and average of 33%, which would also mean 33% less Carbon in the atmosphere. What is Congress waiting for.
In fact, the House passed an energy bill today that did not include any increase in MPG standards. The Senate version calls for an increase to 35 MPG average by 2020.