Cummins has successfully completed the Light Duty Efficient Clean Combustion (LDECC) cooperative program with DoE. This program was established in 2007 in support of the Department of Energy's Vehicles Technologies Advanced Combustion and Emissions Control initiative to remove critical barriers to the commercialization of advanced, high efficiency, emissions compliant internal combustion (IC) engines for light duty vehicles. Work in this area expanded the fundamental knowledge of engine combustion to new regimes and advanced the knowledge of fuel requirements for these diesel engines to realize their full potential. All of the following objectives were met with fuel efficiency improvement targets exceeded: (1) Improve light duty vehicle (5000 lb. test weight) fuel efficiency by 10.5% over today's state-of-the-art diesel engine on the FTP city drive cycle
(2) Develop and design an advanced combustion system plus aftertreatment system that synergistically meets Tier 2 Bin 5 NOx and PM emissions standards while demonstrating the efficiency improvements
(3) Maintain power density comparable to that of current conventional engines for the applicable vehicle class
and (4) Evaluate different fuel components and ensure combustion system compatibility with commercially available biofuels. Key accomplishments include: (1) A 25% improvement in fuel efficiency was achieved with the advanced LDECC engine equipped with a novel SCR aftertreatment system compared to the 10.5% target
(2) An 11% improvement in fuel efficiency was achieved with the advanced LDECC engine and no NOx aftertreamtent system
(3) Tier 2 Bin 5 and SFTP II emissions regulations were met with the advanced LDECC engine equipped with a novel SCR aftertreatment system
(4) Tier 2 Bin 5 emissions regulations were met with the advanced LDECC engine and no NOx aftertreatment, but SFTP II emissions regulations were not met for the US06 test cycle - Additional technical barriers exist for the no NOx aftertreatment engine
(5) Emissions and efficiency targets were reached with the use of biodiesel. A variety of biofuel feedstocks (soy, rapeseed, etc.) was investigated
(6) The advanced LDECC engine with low temperature combustion was compatible with commercially available biofuels as evaluated by engine performance testing and not durability testing
(7) The advanced LDECC engine equipped with a novel SCR aftertreatment system is the engine system architecture that is being further developed by the Cummins product development organization. Cost reduction and system robustness activities have been identified for future deployment
(8) The new engine and aftertreatment component technologies are being developed by the Cummins Component Business units (e.g. fuel system, turbomachinery, aftertreatment, electronics, etc.) to ensure commercial viability and deployment
(9) Cummins has demonstrated that the technologies developed for this program are scalable across the complete light duty engine product offerings (2.8L to 6.7L engines)
and (10) Key subsystems developed include - sequential two stage turbo, combustions system for low temperature combustion, novel SCR aftertreatment system with feedback control, and high pressure common rail fuel system. An important element of the success of this project was leveraging Cummins engine component technologies. Innovation in component technology coupled with system integration is enabling Cummins to move forward with the development of high efficiency clean diesel products with a long term goal of reaching a 40% improvement in thermal efficiency for the engine plus aftertreatment system. The 40% improvement is in-line with the current light duty vehicle efficiency targets set by the 2010 DoE Vehicle Technologies MYPP and supported through co-operative projects such as the Cummins Advanced Technology Powertrains for Light-Duty Vehicles (ATP-LD) started in 2010.