Cummins Inc. and Eaton Corp. have devised a fuel-saving, integrated engine-transmission combination that will rival proprietary offerings from some truck builders.

The upcoming “Powertrain Package” combines an Eaton Fuller Advantage Series automated mechanical transmission and Cummins’ ISX15 with new SmartTorque2 ratings.

Cummins and Eaton representatives said it will be available from many truck brands this fall for linehaul, regional-haul and less-than-truckload applications.

The powertrain should deliver as much as 6% better fuel economy compared to current products and reduce life-cycle and maintenance costs for owners, reps said at a press conference Sunday at the American Trucking Associations' annual Technology & Maintenance Council meeting in Nashville, Tenn.

Key is “downspeeding” the engine’s cruise RPMs from 1,270 to 1,170 at a fleet’s target road speed, the representatives said. This is done with small ratio steps and overdrive top gearing in the 10-speed transmission and pairing it with special ratings for the ISX15.

Two ratings, 415 horsepower and 1,150 to 1,450 pound-feet, and 450 hp and 1,550 to 1,750 lb-ft., are exclusive to this product, they said.

The Powertrain Package is the result of a long-standing cooperation between the two companies. 

"This latest chapter in our partnership combines some of the best technologies from both companies, and makes them smarter, delivering the level of fuel economy improvements that our customers have come to expect," said Lori Thompson, Cummins vice president, truck and bus OEM business.

"The collaboration between the Eaton and Cummins teams has resulted in a superior Powertrain Package with which both fleet owners and professional drivers will be thrilled," said Tim Sinden, president of North American truck operations, Eaton's Vehicle Group. "The level of integration between this transmission and engine is best in class in the North American heavy-duty truck market."

Through hardware and software enhancements, the Powertrain Package’s benefits include:

• Integrated power, fuel and shifting strategies to provide 3% to 6% fuel economy improvement for linehaul and regional haul applications.

• Optimized engine and transmission communications and new control logic that enable further engine downspeeding in the overdrive position, and the effective use of direct-drive gearing in certain operational conditions.

One of the main enhancements Eaton has made with its Fuller Advantage Series transmissions is the elimination of the oil cooler, Sinden said. This helps reduce overall weight and improves reliability. A new lubrication system delivers lube oil precisely and efficiently, further enhancing fuel economy by reducing churning losses.

Combined with the use of aluminum for the rear transmission housing, range cylinder, shift-bar housing and the shift tower - along with a thin wall, cast iron main case design – weight is 75 pounds less than Eaton's UltraShift Plus LAS base model. 

Cummins’ new ISX15 SmartTorque2 ratings are the next generation of today's SmartTorque ratings, and precisely manage the power needed for the load demand, Thompson said. A new feature, Vehicle Acceleration Management, limits excessive gaining of speed which saves fuel and allows the transmission to shift more smoothly.

This feature contributes to fuel economy benefits in stop-and-go duty cycles. The Powertrain Package is undergoing field testing with various sized fleets, and initial testing and customer validation results are confirming the expected fuel economy benefits, Thompson and Sinden said.

The integrated package will be backed by Eaton's Roadranger program and Cummins’ distributor network when the powertrain package goes into production this fall.