Greiner, J., Grumbach, M., Dick, A., and Sasse, C., "Advancement in NVH- and Fuel-Saving Transmission and Driveline Technologies," SAE Technical Paper 2015-01-1087, 2015, doi:10.4271/2015-01-1087.
Market trends clearly demonstrate the ongoing worldwide acceptance and success of modern automatic transmission solutions (AT, CVT, DCT) in both passenger cars and light trucks. This success is based on the further development of the driving comfort, shifting dynamics and - most important - the fuel consumption reduction modern automatic transmission systems offer.First, key driveline parameters such as overall spread and number of ratio's are to be discussed. The optimum spread for the fuel efficiency is in the range of about 8 to 9 and can typically be achieved by 8 to 10-speed transmissions. This is because modern gasoline or diesel-engines have a rather flat characteristic fuel map. Therefore the inner efficiency of the future transmissions becomes increasingly important.The second generation of ZF's 8HP automatic transmission is now introduced which was designed to be used in combination with the latest engine technology that most notably features both downsizing and down speeding. The second generation 8HP features an overall increase in spread with optimized components and new functions.Further options to reduce fuel consumption, packaging, and weight even further are described. A revised oil supply, the use of dog clutches and additional overall spread which makes this possible.The production figures of ZF's Saarbrücken plant have been increased dramatically the recent years. Some innovations in manufacturing are described, which also made this possible.