I have a start-stop car that is somewhat annoying. Driving to school each day, I follow a route that includes a three-mile stretch with five traffic lights. Because the red lights have been synched to curtail speed, I start and stop repeatedly. If I drive to NYC during the same day, I could start and stop (and hear the engine rev rather loudly) maybe 20 times.
The goal is energy conservation and emissions reduction. But is start-stop the best way?
The CAFE Menu
In 2012, NHTSA (National Highway Traffic Safety Administration) said its CAFE (Corporate Average Fuel Economy) mandate was a 27.5 mpg average for new cars. While now mpg targets vary with car size, we can say that the approximate current goal is up to 37.8 and for 2025, it will be 54.5 mpg.
Below you can see a summary of the CAFE fuel economy mpg targets for cars:
For a start-stop car, a Ford executive tells us that the savings can average three to five percent. However, for someone in NYC traffic or a rush hour jam, the benefits can spike to 10 percent, especially if the wait is relatively long. Still though, a typical driver will save maybe $40 a year, not enough to appreciate the technology.
Our Bottom Line: The CAFE Incentive
Although most of us will not ask for start-stop, Ford, Buick and Fiat Chrysler are among the auto manufacturers who are planning to add it to more than half of their cars. Auto manufacturers also have the incentive to produce hybrids and lighter cars, diminish tire rolling distance and increase the number of transmission speeds.
As economists who know that the law of demand is what really makes us conserve–raise the price enough and we buy much less–we can ask why we use the CAFE approach. After all, in the U.K. we have a per gallon gas tax of $3.44 and a Ford Fiesta with an mpg average of up to 65.7 miles. In the U.S. with an average tax of 47.99 cents, the mpg number for the Fiesta is 31 (city and country combined).
But, will you vote for a politician that supports higher taxes or start-stop? And which would you really prefer?