A new engine/powertrain combination developed by Cummins Inc. that’s fueled by E85 (an ethanol/gasoline blend)  cuts carbon-dioxide (CO2) emissions by 50% to 80% vs. a baseline gasoline-powered medium-duty truck, according to the manufacturer.

Dubbed the ETHOS engine by Cummins, the 2.8L powerplant was designed specifically to run on E-85, which the engine maker describes as a “clean-burning blend” of 85% ethanol and 15% gasoline.

Cummins said that “to take full advantage of the favorable combustion attributes and potential of E85, the engine operates at diesel-like cylinder pressures and incorporates advanced spark-ignition technology” to “deliver the power (up to 250 hp) and peak torque (up to 450 lb-ft) of gasoline and diesel engines nearly twice its 2.8L-displacement.”

The engine maker said that the over 1,000 miles and 1,500 hours accumulated on the ETHOS 2.8L over the past 2.5 years shows that “this technology is capable of far exceeding the 50% CO2 emissions reductions outlined in the project's goals.”

A final on-road validation testing phase has been underway in the Sacramento, CA, area since June and will continue into this month.

"The Cummins ETHOS engine, developed through a research partnership with the California Energy Commission (CEC), clearly demonstrates that by combining innovative engine design and combustion approaches with low-carbon alternative fuels, we can determine a path to significant reductions in greenhouse gas (GHG) emissions," said Wayne Eckerle, vice president-- Research & Technology for Cummins.  He noted that the engine maker is very appreciative of the CEC's funding participation in this important effort."

The ETHOS incorporates an integrated stop-start system to further reduce fuel consumption and emissions. In stop-start mode, the engine shuts down after the vehicle comes to a complete stop and the brake pedal remains depressed, Cummins explained. As the driver's foot is lifted from the brake, the system automatically starts the engine “to seamlessly allow acceleration from the stop.”

In addition, Cummins-integrated specific system controls, along with a robust starter, smart alternator and sensors, combine to handle the additional stop-start duty cycle and maintain reliable operation over the life of the engine, the company stated.

Cummins said it also worked closely with Allison Transmission to integrate that company’s 2000 Series transmission into the powertrain to ensure “smooth and efficient stop-start operation,” noting that the transmission is equipped with hydraulic circulation features “to ensure smooth operation and quick vehicle launch during stop-start driving.”

Additional partners in the project included Valvoline, which provided NextGen engine oils specifically designed for lower CO2 emissions, and Freightliner Custom Chassis Corp. (FCCC), which provided a prototype MT45 Class 5 step-van vehicle.