Car Tech

Stop-Start Engines Lead to Big Gains in Auto Efficiency

Like idle hands, idle vehicle motors are a big threat. They waste energy and cause pollution. Simple technology solutions that shut off engines when they’re not in use can lead to huge savings.


We hear about climate change every day. The growing need to address our impact on the environment is almost inescapable in modern society. Engineers have worked across all industries to innovate for the greater good. Solar panels, hybrid cars, and recycling all offer ways for the average consumer to make a serious difference, but many resist the idea of such grand change. It falls to subtler, simpler technologies to recruit the mass populace into the war against global warming.

One such technology is the stop-start, or microhybrid, car. These vehicles still run almost exclusively on gas, but will be one of the most important catalysts for fuel efficiency in the next decade. Stop-start technology is simple: when your car pulls up to a red light or stops dead in brutal rush-hour traffic, the engine will simply shut off. An auxiliary battery provides the power necessary so you can keep jamming to your favorite radio station or power the air conditioning on a hot summer day. According to Car and Driver, Ford claims that its 2012 models using the technology can increase fuel efficiency by up to 10 percent. In effect, stop-start eliminates fuel wasted when cars idle.

This simple yet very effective technology is already widely used in Europe, according to the New York Daily News: 40 percent of new cars sold on the continent employ the technology. Yet consumers in the U.S. have widely resisted the implementation of stop-start tech.That’s likely to change. As emissions standards get harder to meet with standard vehicles, many see microhybrids as the best option. John Nielsen, AAA’s director of automotive engineering and repair, is a proponent of the innovation. “This technology is only going to gain momentum as vehicle manufacturers work to meet more stringent corporate average fuel-economy standards.”

The benefits of microhybrids are clear. Just check out one small example. The Hampton Roads Transit department in Virginia spent about $3,500 to install switches that automatically turn off bus engines after 30 minutes of idling. The department says that its 281 buses will save $1.1 million on gas annually as a result. That’s an immense return on investment. With savings like that and the consistent pressure on our nation to become more efficient, it will be hard for U.S. consumers to ignore microhybrid technology for much longer.