Set to debut in the 2014 Jeep Cherokee, the EcoTrac Disconnecting AWD driveline system is designed to improve fuel efficiency by disengaging components from the driveline when not required, so that only power is delivered to the front wheels.
Back in February we reported that Jeep was taking a back-to-the-future approach in 2014 with the relaunch of the Cherokee. And while the resurrection of this classic was met with a mixed response from our readers, mostly critical of the same-sameness of the SUV design unveiled, we can now expand on how Jeep hopes to realize “fuel economy improvements of more than 45 percent” claimed at the time. This will in part be achieved by EcoTrac.
Produced by American Axle and Manufacturing (AAM), EcoTrac is billed as "the automotive industry's first disconnecting all-wheel-drive (AWD) system." It improves fuel economy by disengaging rotating parts of the driveline when not in use. According to AAM, the system saves 0.75 hp at 65 mph.
The technology effectively cuts the driveline in half, disconnecting the power transfer unit (PTU) and rear drive module (RDM) when in front-wheel drive mode. This reduces inertia and drag created by the movement of unnecessary components associated with powering the rear wheels.
EcoTrac can either be activated directly by the driver or automatically by the electronic control unit, which kicks-in under conditions such as rain, change in slope or change in temperature. These trigger points can also be customized by the driver.
When the control unit detects AWD is needed, the system engages utilizing a wet clutch in the RDM to bring the rear driveline up to the same speed as the PTU. This is designed to provide a seamless engagement of AWD without any interruption to the driver or vehicle performance. The system reverts back front-wheel drive mode once it senses conditions are suitable.
To date AMM has been granted five US patents for EcoTrac and has another nine pending.
Source: AMM
