The Journey is a vehicle CGA says takes the practicality of a people-mover, the capability of a sport-utility vehicle (SUV) and the overall efficiency of a passenger car and blends all the best attributes of each into an all-new “right-sized” crossover for the Dodge brand.
CGA says the dual-clutch transmission, developed in conjunction with gearbox maker Getrag, will provide consumers a fuel economy improvement and CO2 emissions reduction of six percent.
Frank Klegon, Executive Vice President – Product Development, said: “Chrysler’s new dual-clutch transmission is the next step in transmission technology, offering consumers improved fuel economy along with smoother and quicker shifting.”
“This important technology is one of several initiatives we have in place to directly focus on improving fuel efficiency across our vehicle line-up.
Chrysler says its dual-clutch transmission technology improves fuel economy and CO2 emissions by reducing parasitic losses—first, by eliminating the torque converter, and second, through the use of synchronizers instead of shift clutches.
In its first Chrysler LLC vehicle applications, the new dual-clutch transmission will debut in international markets on the all-new 2008 Dodge Journey when mated to the turbo diesel variant.
Originally developed by Volkswagen, which calls its DSG, the dual-clutch transmission is an automatic transmission which utilises dual launch and shift clutches with a manual transmission style lay-shaft gear arrangement, instead of a conventional torque converter and planetary gears.
During shifts, the next gear is anticipated and pre-selected. Then one clutch is opened while the other is closed, allowing shifting without torque interruption. The result is quicker acceleration and refined shift quality. Further, with the lay-shaft arrangement of gears, there is increased flexibility to optimise gear ratio selection for performance and fuel economy.
The Chrysler/Getrag version of the dual-clutch transmission does not require a torque converter to transfer engine torque to the transmission. Instead, it uses two wet multi-plate clutches. With the wet multi-plate clutch system, the clutch components are bathed in lubricating/cooling fluid in order to provide adequate thermal capacity.
The wet multi-plate clutch system uses hydraulic pressure to actuate the clutches and provide for gear selection.
With this system, the power flow from the engine to the transmission is not interrupted during a shift, resulting in a power-on shift.
This means that there is less torque disturbance than a conventional planetary automatic transmission with torque converter.
Also, by eliminating the torque converter and reducing the number of shift clutches, parasitic losses are reduced leading to improved fuel economy.