Truck engine manufacturer Cummins has linked with an American technology company to successfully cut diesel engine exhaust emissions and fuel consumption – using cylinder deactivation control software.
Cummins and Tula Technology say that they have used diesel Dynamic Skip Fire (dDSF) to achieve "significant reductions in emissions and fuel consumption."
The project started early last year, with the goal of optimising the Dynamic Skip Fire (DSF) technology that has made Tula "a tech leader in improving propulsion efficiency and reducing emissions in passenger cars" – aiming to achieve the same result for trucks and buses.
The joint development team modified the engine system to integrate and leverage Tula's DSF control algorithms to command combustion or deactivation on a cylinder event basis. 
The two companies say that continuing development of the programme is expected to help address future, more stringent NOx (oxides of nitrogen) diesel engine exhaust emissions regulations. 
The technology achieves the NOx reduction primarily by optimised exhaust temperature control, resulting in dramatically improved conversion efficiency of the aftertreatment system. The technology achieves CO2 reductions through improvements in combustion and reductions in pumping work. 
Cummins' director, advanced system integration, Lisa Farrell, says: "At Cummins, it's our mission to power a more prosperous world. We do this by helping customers succeed through innovative and dependable products that are good for the customer and the environment. 
"We will continue to innovate the diesel engine system to make it lighter, more reliable, powerful and fuel-efficient, and we are encouraged by the progress demonstrated in this collaboration and what it could mean for future diesel technology." 
The collaboration work was carried out on a Cummins X15 Efficiency Series 6-cylinder diesel engine, which Cummins says already offers class-leading fuel economy.
It was operated using the "challenging" low-load test cycle currently being proposed by the California Air Resources Board – whereby emissions are tested during sustained low-load engine operation, which CARB says "constitutes a large fraction of how trucks actually operate in urban areas."
Modelling of dDSF technology predicted reductions in NOx emissions while simultaneously reducing CO2.   
Tula Technology president and CEO R. Scott Bailey says that the partnership with Cummins "has given us the opportunity to expand our DSF technology beyond its success in gasoline engines. 
"Demonstrating the capability to improve fuel efficiency while also achieving very effective emissions control is extremely important for all diesel engine applications in the future."
The collaboration plans to explore future system optimisation and viability to control noise, vibration and harshness in commercial vehicle applications.