Stefan Sommer, CEO of transmission maker ZF was on hand to discuss the trend in adding more gears to automatic transmissions. For those used to four and five speed versions, the news of vehicles having up to eight gears seems like overkill. But Sommer is confident that 9 speeds will prove to be the best number of gears. It would be interesting to see what other automotive experts recommend because while 9 gears have closed the efficientcy gap, it is believed there is still 11% to go in order to reach what could be considered “perfect”. Some automakers seem to think that adding one more gear to that is the best choice.
“There is no hard line, but you have to consider the law of diminishing returns. The question is whether adding even more gears makes sense,” he said, speaking at the Automobilwoche Congress in Germany. Back in July, ZF North American president Julio Caspari voiced similar statements, agreeing about the 11% gap to reach the perfect efficiency for transmissions. The question seems to be if an additional gear will close that gap or just be “too much.”
General Motors and Ford have recently teamed up to create a ten speed transmission and Hyundai has been working on their own version as well. Chrysler also has plans. They will be adding eight and nine speed transmissions on their production models as early as next year. ZF expects to enjoy the increased sales gains from Chrysler for these new projects. The eight speed transmissions have been going into cars and light trucks and will be used in the Chrysler 300 and Dodge Charger models starting next year.
Another new development on board for the additional gears for next year is ZF will begin assembling nine speed gearboxes in an American based plant close to Greenville, South Carolina. Chrysler is producing these gearboxes under license in Kokomo, Indiana.
Source: Automotive News Europe