Cummins Shows its Most Efficient Heavy-Duty Diesel Yet

4 May 2005

Cummins, working with the US Department of Energy (DOE) as part of the 21^st Century Truck Partnership, has demonstrated a diesel ISX heavy-duty truck engine with an increased Brake Thermal Efficiency (BTE) of 45% while reducing emissions to levels associated with the future 2007 EPA requirements.

Brake Thermal Efficiency represents in percentage terms the amount of energy converted from fuel into useful mechanical work by the engine. A engine with a higher BTE level is more efficient, offering the potential for increased fuel efficiency and associated reductions in CO₂ emissions.

Cummins reduced PM emissions to 0.01 gram/hp-hr by utilizing a Cummins Particulate Filter, while in-cylinder combustion control cut NO_x to 1.2 gram/hp-hr.

Current heavy-duty engines meeting the EPA 2002 emissions requirement typically achieve a BTE of 41%–42%. An earlier version of the Cummins concept engine delivered 44% BTE last fall. (Percentage point improvements in this are hard-earned.) The program’s target is 50% BTE and the further reduction of emissions required by the 2010 standards: 0.2g/hp-hr NO_x and 0.01 g/hp-hr PM.

Cummins achieved the efficiency on the ISX engine with dual EGR (Exhaust Gas Recirculation) valves and coolers through a combination of tuning the combustion performance, optimizing the thermal management strategies for aftertreatment of the exhaust and regeneration of the particulate filter, and reducing parasitic load on the engine by replacing water and lube pumps.

Resources:

• 21st Century Truck Partnership program page

• Heavy-Duty Truck Engine: 2007 Emissions with Excellent Fuel Economy