THE DRIVE FOR HIGHER FUEL EFFICIENCY IS DRIVING THE NUMBER OF TRANSMISSION GEARS UP AS CHRYSLER OFFERS THE 9 SPEED, HYUNDAI TO OFFER THE 7 SPEED, AND MERCEDEZ BENZ ITS OWN 9 SPEED–THE DESIGN OSBTACLE IS TO OVERCOME WITH LESS WEIGHT WITH MORE GEARS

Hyundai Motor in its new i40 launch promoted the fact that the sedan has a seven-speed dual clutch transmission.
Mercedes-Benz stressed in its E220 Bluetec launch that it has rolled out the first E class with a nine-speed auto transmission, while Chrysler touted that their 200 is a segment-first mid-size sedan with a nine-speed gearbox.
For local carmakers, Hyundai's Genesis and Equus luxury sedans and Kia K9 have the highest gear counts with an eight-speed gearbox.
On the back of increasing demand for a higher fuel economy, the local car market is racing to offer more gears on a wider spectrum of cars as well.
Transmission is the part that creates the power along with the engine. When the vehicle has a higher gear count it is like having more steps for climbing a building. It enables driving at lower revolutions per minute, thus consuming three to eight percent less fuel.
But automakers cannot blindly chase for more gear counts, because it will make the gearbox heavy, thus compromising fuel efficiency.

http://www.koreatimes.co.kr/www/news/biz/2015/02/388_173641.html