NASHVILLE — Cummins and Eaton announced a new powertrain package for heavy-duty trucks this morning, one that the companies said will deliver a three to 6 percent fuel economy improvement, lower preventative maintanance and total life cycle cost improvements.

Combing Eaton’s Fuller Advantage Series automated transmission with Cummins ISX15 SmartTorque 2 ratings, the product, company executives said, is the result of a long relationship.

The Eaton Fuller Advantage Series automated transmission will be offered as a small ratio step overdrive model with new Cummins ISX15 SmartTorque2 ratings: ISX15 415 ST2 with 1450 lb-ft to 1650 lb-ft. of torque, and the ISX15 450 ST2 with 1550 to 1750 lb-ft. of torque.

The powertrain package includes integrated power, fuel and shifting strategies that provide a 3 to 6 percent fuel economy improvement for linehaul and regional haul applications, the companies said. That fuel economy improvement was benchmarked against comparable ISX15s and Eaton transmission combinations.

Engine and transmission communications have been optimized and new control logic allows for further engine downspeeding in the overdrive position.

Eaton eliminated the cooler from the transmission, which helped reduce overall package weight and improved reliability, they said. Aluminum was used for the rear transmission housing, range cylindar, shift bar housing and the shift tower. “Along with a thin wall, cast iron main case design, this results in the new transmission weighing 75 pounds less than Eaton’s Ultrashift Plus LAS base model,” they explained. A precision lubrication system also improves fuel economy by reducing churning losses, Eaton noted.

Cummins ISX15 SmarTorque2 ratings are the next generation of today’s SmartTorque ratings, and manage, precisely, the power needed for load demand. The Vehicle Acceleration Management (VAM) is an electronic feature that manages vehicle accerlation for smoother shifting, Cummins said of the patented technology. This helps fuel economy in stop-and-go found in regional haul applications, they explained.

Eaton and Cummins stressed that the new package was based on request from customers. Currently, the package is undergoing field testing with various sized fleets, and initial testing and customer validation have confirmed the three to six percent fuel economy improvement.

The package will be available in the Fall of 2013.