Hybrids already do it. Many drivers do it independently. So when will fuel-saving engine shutoff systems start coming to more vehicles?
It's well known that idling in traffic or at stoplights accounts for both wasted fuel and some of the most damaging emissions.
In fact, Consumer Reports says that much of the fuel savings showing up in the mileage estimates for mild hybrids actually comes from automatic engine shutdown during idling.
European and Asian automakers have begun bringing idle-shutdown systems to ordinary gas cars in their home markets, but not to their similar U.S. models. Who has got them? And why aren't there more here?
BMW, for one, uses a shutoff system on its four-cylinder European models that gets fuel savings of 5%. It will bring the feature to its U.S. vehicles. Mazda also has it on the Mazda3 in Europe. Ford, Kia, Audi and Mercedes-Benz are working on similar systems.
Right now in the U.S., vehicles like the Porsche Panamera and the upcoming 2011 Cayenne have a push-button auto start/stop system that must be manually activated.
Why the slow adoption in the U.S. when real-world fuel savings are estimated to be 5% to 10% in congested traffic and emissions are lowered? It's a tough call for automakers, largely because the way the Environmental Protection Agency calculates gas mileage ratings doesn't factor in much idling time. Start-stop systems can add a few hundred dollars to the price on the sticker, but don't show up in better government gas mileage ratings on the sticker. The better mileage and lower emissions are counted in Europe.
source: usatoday
