GM: Eight-Speeds on the Way

GM: Eight-Speeds on the Way


New gearboxes being studied.
by Joseph Szczesny (2007-10-15)


2008 Chevrolet Corvette


General Motors isn't giving away any of the specifics just yet, but it does have a seven- and even an eight-speed automatic transmission tucked away in its product development cycle.



Jim Lanzon, executive director of GM Powertrain's Transmission Engineering, acknowledged last week GM is looking at the transmissions that have begun showing up on luxury models such as the BMW M5.



"I can't give away any new product news but we're looking at everything," he said.



One of the issues GM is wrestling with now is whether a seven- or eight-speed transmission will produce the kind of gains in fuel economy that would justify the cost of engineering them into a vehicle, Lanzon said.



"There is more to making a seven- or eight-speed transmission than adding more modules. You've got to be concerned about the parasitic losses that neutralize the fuel-economy gains," he said.



Lanzon emphasized GM already has the skills needed to put a seven-speed or eight-speed transmission into production very quickly and at relatively low cost. In the past four years, GM, with the aid of computerized tools, has launched nine new six-speed transmission models. In the past, GM would spend a decade developing three or four new transmissions.


The new technology utilized by GM has shaved as much as six months and $15 million from the typical development of a transmission, Lanzon said. The technology also saved the company more than $100 million during the latest development cycle, which has put six-speed transmission in everything from the Chevrolet Corvette to mid-size crossover vehicles, he said.



The technology also has helped boost the quality and dependability of the new units, which have had few changes, Lanzon said. Not only are the costs down, but the quality has improved, he said.



Lanzon said GM's transmission engineers are using sophisticated math modeling, among other advanced tools, to not only design the transmission components, but also to predict and test their reliability, analyzing functions such as oil pressure and flow, lubrication distribution and shift quality.