Nissan and JATCO develop next-generation CVT


(July 2009) Most of Nissan's American lineup operates with CVTs or continually variable transmissions — transmissions that have an infinite number of gear ratios.

CVTs can generally provide better fuel economy than other transmissions by enabling the engine to run at its most efficient rpm over a range of vehicle speeds.

Nissan has committed to the CVT for the long term based on an announcement Sunday that Nissan and transmission supplier JATCO Ltd. are jointly developing a new generation of compact and lightweight CVTs.

The next-generation CVT design features an innovative structure combining conventional CVT belt operation with an auxiliary gearbox and a significantly increased gear ratio range. The new CVT is scheduled to appear in  compact Nissan vehicles worldwide in the near future, Nssan said.

The new transmission features Adaptive Shift Control (ASC), which improves performance by automatically selecting the best ratio for startup, acceleration and uphill or downhill driving. It combines a belt-operated CVT with an auxiliary transmission, shortening its overall length by 10 percent and reducing weight by 13 percent compared to conventional CVTs in its class. And, Nissan says, the new structure raises the available transmission ratio from current 6.0:1 to 7.3:1, more than 20 percent higher than other CVTs, for enhanced responsiveness on starting and acceleration.

"Nissan believes the CVT has very good potential as a leading technology for raising the fuel efficiency of internal-combustion engine systems," said Shuichi Nishimura, corporate vice president, Nissan Powertrain Engineering Division.