Already used in Europe, Ford's fuel-saving system turns off the gas engine when a car is idle to improve efficiency by up to 10 percent.
Ford today said it plans to bring start-stop technology to the U.S. in 2012 in order to improve fuel economy by a modest amount at a relatively low cost.
Start-stop technology, which is also called microhybrid or idle-stop technology, turns off a vehicle's engine when the car is not moving.
On-board energy storage keeps the car's electrical system working for functions such as heating and lights. When the driver puts a foot on the accelerator, the engine turns back on. The on-board battery is charged when the driver slows downs and helps move the car from idle.
This fuel-saving feature, called Auto Stop-Start by Ford, is now used in the company's hybrid cars, such as the Ford Fusion hybrid. Starting in 2012 in the U.S., it will be built into conventional diesel and gasoline cars, crossovers, and SUVs, Ford said.
Ford plans to introduce this technology to all the countries in which it operates, saying that the system can improve fuel efficiency between 4 percent and 10 percent without sacrifices or changes to driver behavior. The technology is already used in different Ford models in Europe.
Use of start-stop technology is driven by Europe's stricter emissions and fuel economy standards, according to Lux Research, which projected rapid growth for start-stop technology in a report (PDF) last month.
Lux projected that sales of microhybrid vehicles will top 3 million this year and grow rapidly over the next five years to 34 million units by 2015.
Microhybrids are the most cost-effective way to meet mileage and emissions goals because automakers don't need to use expensive nickel-metal hydride or lithium-ion batteries, according to Lux. With relatively little energy storage needed, automakers can use cheaper storage, such as lead-acid batteries or ultracapacitors.
Ford's Auto Start-Stop system uses a 12-volt auto battery and an upgraded starter motor, said Birgit Sorgenfrei, program manager for Auto Start-Stop, in a statement.