How many gears can a transmission hold?

Cars with six or seven speed automatic gear boxes some even with dual clutches are becoming the norm nowadays. Yet the Powerglide was an automatic transmission designed by General Motors and was mainly on Chevrolet models from 1950 till the 1973. With just two gears, it was considered state of the art at launch. The future has arrived indeed.

ZF Friedrichshafen (ZF), a well-known German transmission supplier is working on a nine-speed automatic that will be introduced next year, and there have been online reports claiming Hyundai is trying to incorporate a ten gear transmission.

ZF North American president Julio Caspari, cited that the gear race is reaching its limits and marketing is a bigger factor than engineering when having transmissions with more gears. According to him, there is only an 11 percent difference between the best transmissions today and a perfect unit in theory.

Cost-effectiveness for building a "perfect" transmission is also taken into consideration, where expensive materials, like ceramic ball bearings might be required to reduce friction.