• NATALIA SOUSA

Cummins and Tula Study of Diesel Dynamic Skip Fire (dDSF™) Shows 74% Reduction in NOx Emissions

Cummins Inc. and Tula Technology, Inc, announced in Detroit the results of their collaborative study on the effectiveness of Tula’s diesel Dynamic Skip Fire (dDSF™) in reducing nitrogen oxides (NOx) and carbon dioxide (CO2) emissions on a Cummins X15 HD Efficiency Series diesel engine.

Tula’s dDSF technology provides significant benefits to reduce NOx and CO2 emissions under low-load vehicle operation, which will aid our efforts to produce more reliable, more powerful engines while meeting Cummins’ environmental goals.



Low-load cycle performance was estimated with a well-calibrated powertrain simulation tool to capture the low-load system operation and emissions accurately. This system showed a 74 per cent reduction in NOx and a 5 per cent reduction in CO2 compared with today’s clean diesel technologies. Compared to current engine technologies and modifications to the thermal management techniques, dDSF saved 20% in fuel, validating dDSF as a more fuel-efficient means of reducing NOx.


Cummins and Tula demonstrated the positive dDSF results in a Class 8 truck powered by a Cummins X15 HD engine. The dDSF test results highlight a promising technical advancement for an industry seeking strategies to address future, more stringent NOx emissions regulations for diesel engines.


“Our mission at Cummins is to make people’s lives better by powering a more prosperous world, and we accomplish this through innovation,” said Lisa Farrell, Director, Accelerated Technology Center for Cummins Inc.

“Tula’s dDSF technology provides significant benefits to reducing NOx and CO2 emissions under low-load vehicle operation, which will aid our efforts to produce more reliable, more powerful engines while meeting our environmental goals.”


“NOx standards are becoming progressively more stringent for diesel engines, and meeting those standards is increasingly challenging, even for a class-leading, efficient engine like the Cummins X15 HD,” said R. Scott Bailey, president and CEO of Tula Technology. “Our dDSF is a powerful and unique technology that enables original equipment manufacturers to significantly reduce NOx emissions that contribute to smog while simultaneously reducing fuel consumption and greenhouse gas production. We appreciate the opportunity to work with Cummins to demonstrate the capability of our technology.”


Dynamic Skip Fire is an advanced cylinder deactivation control strategy that makes decisions for an engine’s cylinders on an individual basis to meet torque demands best while saving fuel and maintaining performance. Tula’s original Dynamic Skip Fire (DSF®) software has been shown to reduce CO2 emissions in gasoline engines significantly. It has been in production since 2018, with more than one million vehicles on the road. dDSF is the Dynamic Skip Fire application for diesel engines.

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