Everyone knows that all of the car manufacturers have been hard at work over the past couple of decades trying to improve gas mileage, but how effective have those efforts been? New research conducted by a Christopher Knittel of the Massachusetts Institute of Technology (MIT) shows, in a report published on MITnews, that while such efforts have resulted in newer and generally better technology, the overall results are less than positive. He goes so far as to say that despite such efforts, vehicles on the road today don’t get much better mileage than did vehicles twenty years ago.
There’s a simple explanation for this, he explains, and that is the fact that the weight of cars has increased over the same time span. Part of that is due to the popularity of minivans, pickup trucks and of course SUVs, but part of it is due to customer demands. Knittle says that because customers buy cars with a smoother ride, manufacturers add features that make a ride smoother, and that almost always causes a car to become heavier. Then, to deal with the extra weight, car makers are then rather forced to make stronger engines with more horsepower, which of course lowers gas mileage.
On a more positive note, Knittle also writes that new technology has made modern cars far more efficient than ever before, which can be seen when comparing average miles per gallon in the United States versus other countries where big vehicles aren’t nearly as popular. Fuel-injection systems, multiple camshafts, variable speed transmissions, along with body shells that are less resistant to wind have all contributed to dramatic improvements in efficiency. So much so, he says, that if the average car size and weight were the same today as in 1980, then we’d be averaging 37 miles per gallon collectively, rather than the paltry 27 that we’re actually getting.
And it’s all because cars have gotten so much bigger. By pouring over data from the National Highway Transportation Safety Administration, manufacturer fact sheets, industry journals and a variety of other sources, Knittle was able to determine that cars today are on average 26 percent heavier than they were in 1980; and all that weight takes more energy to move. Most revealing perhaps is the statistic that shows that private trucks and SUVs now account for more than half of all vehicles on the road today.
Thus, it turns out we have no one to blame for low average mileage with our vehicles, but ourselves.