News Summary: GM, Ford join to work on gearboxes

News Summary: GM, Ford to jointly develop 9- and 10-speed automatic transmissions

COOPERATING: General Motors Co. and Ford Motor Co. have agreed to jointly design nine- and 10-speed automatic transmissions for cars and trucks. The companies will build the transmissions separately.

SAVING MONEY: Transmissions cost hundreds of millions of dollars to develop, so the automakers can save millions. It also will bring the new gearboxes to market faster. Currently the highest number of automatic transmission speeds that each company sells is six. They're behind, because some automakers already have cars with eight-speed transmissions on the road.

BETTER MILEAGE: More gears generally mean better performance and fuel economy because they allow engines to work less to keep cars and trucks moving. Analysts say nine- and 10-speed transmissions can raise gas mileage by 5 to 10 percent over six-speed gearboxes.