The Cummins X15 Efficiency Series diesel engine has won the Truck Writers of North America’s 2016 Technical Achievement Award.

The award was presented thsi week during an awards luncheon at the American Trucking Associations Technology & Maintenance Council’s annual meeting in Nashville, Tenn.

Cummins redesigned its ISX15 to meet 2017 federal greenhouse gas and fuel economy requirements and introduced two new versions, the X15 Performance and X15 Efficiency.

The Efficiency version employs an Atkinson Cycle in its valve action that adds fuel efficiency important to fleet managers, said John Baxter, a freelance technical writer, former mechanic, and a member of the TWNA judging panel. That caught the attention of his colleagues in the voting.

“The engine won for its advanced combustion design that includes a little-used Atkinson Cycle, and other features,” explained Jim Park, chairman of the TWNA awards committee and Heavy Duty Trucking equipment editor.  “It beat out four other finalists who had previously topped a pool of 15 candidates for the award. A panel of industry journalists from Canada and the U.S. debated and voted over a period of several weeks.”

The 14.9-liter diesel gains 3% in fuel efficiency over the preceding model, the ISX15, through improvements to air-handling, combustion efficiency, reduced parasitic losses and advanced electronics, according to Tim Proctor, Cummins X15 engine system technical leader. Maintenance should cost 40% less than previous engines over five years.

“The engine’s valve events are modified so that compression is slightly limited, allowing for greater-than-normal expansion during the power stroke that follows,” Baxter explained. “That means that the gases expand to 20 times their volume at the pistons’ top center by the time they are released, as opposed to standard expansion factors in the range of 15-17 to 1. Allowing the burning gases more room to expand captures energy that is normally thrown away when the exhaust valve opens.”

Baxter also observed that the engine also features "a new piston design that conducts heat more effectively away from the combustion bowl and into the cooling system. This takes considerable heat stress off the oil, allowing longer change intervals, and allows use of a smaller oil pump, reducing the parasitic loss associated with driving it. We congratulate Cummins on the originality of their re-design of the X15.”

“Cummins is honored to receive the Technical Achievement Award for our 2017 X15 Efficiency series, and it is especially relevant to us that this recognition comes from truck industry writers, many of whom have experienced the enhanced driveability and responsive performance of the X15 engine first hand,” said Proctor.

The other four finalists were:

• Accuride EverSteel wheel with a special anti-corrosion treatment

• Mack and Volvo “wave” piston, part of engine upgrades to comply with new GHG regulations

• SAF-Holland P89 disc brake, a high-performance, lightweight and moderate-cost braking product

• Volvo iSee and Mack Predictive cruise control, which “learns” routes and operates a truck’s powertrain to gain maximum efficiency

TWNA first presented the Technical Achievement Award in 1991 to Grote Industries for its red LED marker lamp and has since honored companies large and small for their products and services.

Founded in 1988, TWNA is a professional organization composed of writers, editors, public relations specialists, marketing personnel and others involved in the business of creating or producing information related to the world of trucking.

Related: Eaton's Procision Transmission Wins 2015 TWNA Technical Achievement Award