According to American Axle & Manufacturing (AAM), when it introduced its EcoTrac disconnecting all-wheel drive (AWD) system several years ago, the system dramatically increased efficiency, safety and performance. Now, the second generation of EcoTrac will further this mission with even greater system efficiency and packaging gains, AAM says.
Originally launched on the 2014 Jeep Cherokee, AAM’s EcoTrac Disconnecting AWD gives drivers the performance of an AWD vehicle with the fuel economy of a front-wheel-drive vehicle by automatically and seamlessly using only the front wheels when AWD is not required. The EcoTrac AWD system disconnects at the power transfer unit (PTU), so that the driveshaft stops spinning and power is no longer sent to the rear wheels. Less spinning means less fuel consumption and fewer emissions. When the EcoTrac system senses that road conditions necessitate AWD, EcoTrac automatically reconnects the PTU and rear drive module to seamlessly provide AWD.
Launching next year, the second generation EcoTrac is even more efficient, according to AAM. It reduces the system drag of a typical AWD system by more than 90 percent, as compared to 80 percent for the first generation. Furthermore, AAM was able to reduce the size and weight of the EcoTrac system without affecting safety and functionality, the company says.
“AAM’s EcoTrac was a groundbreaking technology that significantly increased fuel economy, vehicle handling and off-road capability,” said Phil Guys, AAM vice president and chief technology officer. “We have raised the bar with our next generation EcoTrac. It is lighter and smaller with increased torque density. This means drivers will see further fuel economy improvement while the reduced packaging footprint will allow our customers the flexibility to incorporate other vehicle systems.”
How EcoTrac works
Using advanced sensors and AAM’s proprietary algorithms, the EcoTrac AWD system monitors and analyzes road conditions and then disconnects many of the rotating components from the driveline when they are not needed. The system disconnects at the power transfer unit (PTU) and the rear drive module (RDM) allowing large portions of the driveline to stop rotating while in front-wheel drive mode, including both the PTU and RDM hypoid gear sets, the bearings associated with the gear sets, and the driveshaft.
“When you add a traditional AWD system to a vehicle, it increases safety, but it also decreases fuel economy by one to three miles per gallon,” said Guys. “AAM’s system offsets that fuel economy penalty but still allows drivers the safety and functionality of an AWD system. It is a win-win for people who are looking for fuel-efficient AWD.”
AAM’s EcoTrac AWD system can be engaged with driver input or when automated transition events (ATEs) occur. AAM software engineers developed the unique codes in-house for the ATEs, which include both environmental and dynamic events such as lower temperatures, rain detection and changes in slope. When it receives the ATE signal from the AAM electronic control unit to engage AWD mode, the EcoTrac system engages AWD seamlessly without noticeable shifting to the driver.
AAM has supplied more than 600,000 EcoTrac AWD units to customers since its introduction. The next generation EcoTrac will launch on a global vehicle in 2018. By the end of 2019, EcoTrac will represent about $700 million of revenue for AAM in global markets.
