Systems-engineering a new 4×4 benchmark

Chrysler Powertrain teamed with AAM to create the industry's most capable, sophisticated-and arguably most fuel-efficient-AWD/4WD driveline. Top engineers talk about their collaboration.

“We set a high target for this program: Create the industry's most fuel-efficient four-wheel-drive system, with the greatest off-road capability and functionality,” said Mike Kirk, Chrysler's Director of Powertrain, Axle, Driveline & Manual Transmission Engineering, about the 2014 Jeep Cherokee. “And we knew from the start that our success was dependent on systems engineering-both internally and in close collaboration with our suppliers.”

Transforming a front-wheel-drive crossover (the KL Cherokee is based on Fiat-Chrysler's modular Compact U.S. Wide car platform) into a benchmark off-roader is no small feat, even without the requirement for a major leap in fuel efficiency-the base Cherokee is EPA-rated at 31-mpg highway. While ZF's all-new 9-speed transmission, known as the 948 within Chrysler, would provide gearing benefits, Kirk's team realized the vehicle driveline also was key to significant efficiency gains.