Cummins Inc. has announced the development of an engine and powertrain that it says reduces CO2 emissions by as much as 80 per cent compared to a baseline gasoline-powered medium-duty truck.
“The Cummins ETHOS engine, developed through a research partnership with partnership with the California Energy Commission, 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 emissions,” said Wayne Eckerle, Cummins Vice President of Research and Technology.
The the ETHOS 2.8L engine has clocked more than 1,000 miles and 1,500 hours over the past 2.5 years, demonstrating that the technology is capable of far exceeding the 50 per cent CO2 emission reductions outlined in the project’s goals.
A final on-road testing phase has been underway in the Sacramento, California, area since June 2014, and continuing into July.
The Cummins ETHOS 2.8L is designed specifically to use E-85, a clean-burning blend of 85 per cent ethanol and 15 per cent gasoline. To take full advantage of the favorable combustion attributes and potential of E-85, the engine operates at diesel-like cylinder pressures and incorporates advanced spark-ignition technology. It delivers the power (up to 250 hp) and peak torque (up to 450 lb-ft) of gasoline and diesel engines nearly twice its 2.8-liter displacement.
The Cummins ETHOS 2.8L engine also incorporates an integrated stop-start system, which further reduces 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. As the driver’s foot is lifted from the brake, the system automatically starts the engine to seamlessly allow acceleration from the stop.
Cummins-integrated specific system controls, along with a robust starter, smart alternator and sensors, are all designed to handle the additional stop-start duty cycle and maintain reliable operation over the life of the engine. Cummins also worked closely with Allison Transmission to integrate the 2000 Series transmission for smooth and efficient stop-start operation. 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, which provided a prototype MT45 Class 5 step-van vehicle.
Using corn-derived E-85, the high thermal efficiency and power-to-weight ratio of this engine results in 50 to 58 per cent lower well-to-wheels CO2 emissions compared with the gasoline engine baseline.
Using second-generation lignocellulosic-derived E-85, the powertrain’s efficiency features deliver an impressive 75 to 80 per cent lower well-to-wheels CO2 emissions, depending on the drive cycle. Cellulosic E-85 is less intensive in terms of land use, tilling, fertilizing and harvesting than corn-derived E-85. Although not in high-volume production today, cellulosic ethanol represents a promising production pathway for future fuels. This demonstrates that significant reductions in GHG emissions can be achieved with current commercially available E-85 fuels, with even greater potential in the future when cellulosic ethanol technology matures and becomes mainstream.
For additional details about the Cummins ETHOS 2.8L engine and California's Ultra-Low Carbon Powertrain Program, please click here.