Ford: 70% of N. American Lineup to Offer Stop-Start by 2017

Ford Motor Co. says it will offer an automatic engine stop-start system in 70% of the models it sells in North America by 2017.

Stop-start systems shut off the engine when the vehicle stops and instantly restarts it as the driver releases the brake. Ford currently offers the option in the U.S. only in 2014 Ford Fusion small sedans equipped with a 1.5-liter EcoBoost 4-cylinder engine.

The technology, already incorporated in Ford's hybrid powertrains, can improve fuel economy 3.5%-10% in city driving, according to the company.

Ford says it will sell more than 500,000 vehicles equipped with stop-start worldwide this year.