that will allow heavy-duty trucks to conserve fuel by adopting “engine downspeeding.” According to Dana, the new axle ratio (2.47:1) means fleet operators may optimize their driveline specifications for better productivity and fuel efficiency.
“Downspeeding” is a strategy for adjusting a vehicle’s powertrain settings, in order to improve fuel economies, especially in relation to U.S. EPA’s greenhouse-gas emissions standards for Class-8 trucks. The process involves increasing the powertrain’s rear gear ratio in order to lower the speed of the engine. This allows the engine to operate at more efficient RPMs with minimal horsepower needed to maintain a cruising speed of 65 MPH.
Dana manufactures drivetrain, sealing, and thermal-management technologies for passenger vehicle, commercial truck, and off-highway equipment. It has nearly 100 engineering centers, manufacturing plants, and distribution centers worldwide.
According to the developer, its new axle-ration is well suited to direct-drive versions of the SmartAdvantage™ Powertrain, a product of Eaton Corp. and Cummins. The configuration is recommended for regional hauling that involves interstate highways, secondary roads, and urban operations.
As described by Dana, the SmartAdvantage is “the most fuel efficient powertrain in the trucking industry,” involving a Cummins X15 Efficiency Series engine and an Eaton Fuller Advantage® 10-speed automated manual transmission. The engine and transmission share critical data, determining the torque needed to provide drivability and optimized power.
By adopting engine downspeeding and taking advantage of the Cummins X15 engine's low-end torque, vehicle operators will see fuel economy improvements compared to traditional drivelines, according to Dana.