Automakers have focused on more powerful engines at the expense of fuel economy for decades. At the time it made sense; not only did Americans seemingly want more horsepower, but gasoline was dirt cheap. But the focus has shifted due to rising gas prices, several oil crises, and federal mandates for better fuel economy. Now a plethora of gas-saving technologies, from turbocharging to hybrid powertrains to electric motors, are finding their way into the engine bays of today’s cars from subcompacts to full-sized sedans.
But are the wrong vehicles receiving the attention? Michael Sivak and Omer Tsimhoni of the University of Michigan’s Transportation Research Institute report that fuel economy, overall, in the U.S., averaged slightly over 17 mpg in 2006, a minuscule increase from the 14 mpg achieved by vehicles in back in 1923. Much of this lack of increase, according to the researchers, could be attributed to medium and heavy trucks, which saw fuel economy rise less than one mpg since the 1960s. Overall fuel economy, argues Sivak, would improve if automakers focused their attention improving the fuel economy on such low-mileage vehicles. “Some of the improvements in effective fuel efficiency will come from the ongoing partial shift from using light trucks to cars for personal transportation,” writes Sivak. “Such improvements could be fostered by tax policies that assist the development and introduction of new relevant technologies and encourage scrapping older vehicles.”
Sivak and Tsimhoni’s research also shows that while car fuel economy saw a spike from over 13 mpg to around 21 mpg by 1991, it barely added one mpg—21.2 mpg to 22.4 mpg—by 2006. MIT economist Knittel writes in his study, “Automobiles on Steroids”, that while increasing vehicle weight (26 percent) contributed to the low fuel economy figures, it was the focus on horsepower—which rose more than 100 percent during the same period of time—that hindered fuel economy. Knittel estimates that, all factors being equal (i.e., car weight, engine horsepower), today’s cars, which average around 27 mpg, would see an increase to around 37 mpg.
Automotive.com’s take: Interesting analysis. Unfortunately, the researchers and economist did not factor the fact that fuel economy is not a major factor for many vehicles, especially medium and large trucks, which are used for an entirely different purpose. Automakers also build their vehicles based on consumer tastes and purchases which only prioritized fuel economy in the past 30 years or so.
Source: New Jersey Newsroom