Cars Weigh Too Much
A century ago the best-selling car in the United States, Ford’s Model T, wrung a watt from every 12 grams of its internal-combustion engine. Now, engines in best-selling American cars are getting a watt per gram—a 92 percent improvement. That is the one bit of happy news I am going to impart today.
Now for the bad news: In the past 100 years average engine power has increased more than 11-fold, to about 170 kilowatts. This means that despite a huge drop of mass/power density, today’s typical car engine is hardly lighter than it was a century ago—and the average car itself has become much heavier: Its mass has roughly tripled, reaching more than 1,800 kilograms (the average for all light-duty vehicles, nearly half of which are pickups, SUVs, and minivans).
And because more than three-quarters of U.S. commuters drive alone, you get the worst ratio of vehicle-to-passenger weight since a mahout last rode a bull elephant to work.