Clean diesel

Ricardo is working on an advanced research project to demonstrate an advanced diesel technology capable of achieving US Super Ultra-Low Emission (SULEV) and Tier II Bin 2 requirements. SULEV vehicles are conventionally powered or gas-electric hybrid vehicles designed to produce minimal air pollution, typically less than 10% of that of an equivalent ordinary vehicle.



According to Ricardo, the objective of this program is to remove the diesel combustion engine from the environmental debate on regulated emissions – allowing advanced diesel engines to take their place alongside gasoline hybrid and fuel cell powered vehicles in the future of environmentally friendly automotive products. Ricardo will undertake the work with a global manufacturer.



Started in late 2005, early project focus has been on developing technologies to deliver engine-out exhaust emissions (without NOx after treatment) that achieve stringent Tier II Bin 5 emission requirements, delivering NOx levels approximately one-sixth those currently proposed for Euro 5. These technologies include advanced air handling systems, two-stage boosting, advanced exhaust gas recirculation and application of closed-loop cylinder pressure-based engine controls.



In parallel, work is being carried out to develop an advanced exhaust after treatment system. Combining advanced after treatment with engine optimisation will allow demonstration of a system capable of meeting the requirements of US SULEV/Tier II Bin 2, thereby achieving NOx levels less than one-tenth of currently proposed Euro 5 levels.



Throughout the project, a major emphasis has been placed on achieving low emissions under transient conditions to maintain or improve the “fun to drive” responsiveness of the engine without deteriorating emissions performance. The engine is being developed with a competitive power rating of 65kW/l to meet US emissions regulations for both sea level and altitude compliance.



These advanced diesel technologies will be integrated into a vehicle capable of meeting the lowest current world-wide exhaust emissions standard (SULEV, Tier II Bin 2) without compromising customer appeal, while maintaining significant fuel efficiency advantage over current US equivalent gasoline products.


Also, by applying a systems engineering approach, combining engine-out optimisation with advanced after treatment, a highly cost effective solution is expected.