Related: Cummins to Offer 18-Speed Endurant Transmission as X15 Engine Option
Cummins, Tula Technology Team Up to Reduce Emissions
Cummins Inc. and Tula Technology, Inc. will collaborate on a technical demonstration of diesel Dynamic Skip Fire (dDSF), which controls cylinder deactivation to reduce emissions and fuel consumption.

Cummins Inc. and Tula Technology used a Cummins X15 Efficiency Series 6-cylinder diesel engine and modified it to incorporate Tula’s Dynamic Skip Fire to reduce emissions and fuel consumption.
Photo: Cummins
Cummins Inc. and Tula Technology, Inc. will collaborate on a technical demonstration of diesel Dynamic Skip Fire (dDSF), which controls cylinder deactivation to reduce emissions and fuel consumption.
Started in early 2019, the goal of this project was to optimize cylinder deactivation strategies for diesel engines to address the upcoming, more stringent NOx regulations.
“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,” said Lisa Farrell, director of advanced system integration at Cummins.
The team used a Cummins X15 Efficiency Series 6-cylinder diesel engine and modified it to incorporate Tula’s Dynamic Skip Fire to control combustion and deactivation on a cylinder event basis. Even with the low-load cycle being proposed by the California Air Resources Board, the modeling of dDSF technology predicted reductions in NOx emissions and CO2.
“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,” said R. Scott Bailey, president and CEO of Tula Technology.
More Fuel Smarts

EPA Proposal Could Ease 2027 Truck Costs and Buying Uncertainty
The proposal doesn't change the tougher NOx standard, but it would revise key implementation requirements that manufacturers say have driven up costs and complicated fleet purchasing decisions.
Read More →
Cummins, Paccar Ease DEF Derates After EPA Guidance
Updated diesel engine software gives truck operators more time to address emissions-system issues while staying compliant with EPA emissions standards.
Read More →
Maintenance in the Messy Middle Part 3: Biodiesel
Biodiesel can reduce emissions, improve fuel-system lubricity and use existing diesel infrastructure. But NACFE’s Messy Middle maintenance report says fleets must actively manage storage, cold-weather operation, filters and oil drain intervals to avoid problems.
Read More →
Enhance Fleet Performance with High-Efficiency Auxiliary Power Units
Drive sustainable cost savings while increasing driver comfort during short- and long-haul logistics operations.
Read More →
Maintenance in the ‘Messy Middle’ Part 2: Renewable Diesel Fuel
NACFE's latest Messy Middle Powertrain Service & Maintenance report says renewable diesel gives fleets an opportunity to reduce carbon emissions without changing trucks, fueling infrastructure or maintenance practices. But technicians still need to understand several important operational differences.
Read More →
The Diesel Engine Enters NACFE’s ‘Messy Middle’
NACFE’s new Messy Middle Powertrain Service & Maintenance report says keeping modern diesel engines running now depends as much on software, diagnostics and data as traditional mechanical service.
Read More →
DTNA Software Update Gives Truckers More Time Before DEF Derates Take Effect
The changes reflect EPA guidance aimed at reducing downtime caused by emissions-system faults while maintaining compliance requirements.
Read More →
New Agentic Predictive Maintenance Report Demonstrates How Degraded Aftertreatment Systems Waste Fuel
Questar analyzed a large mixed-class fleet and discovered it was wasting as much as $30 in fuel per vehicle, per day, because of mechanically degraded aftertreatment systems.
Read More →
New York City's Microhub Project is Delivering Results
Trucking, last-mile delivery companies, and environmental advocates like what they are seeing so far with New York's microhub program.
Read More →
Lessons Learned About Alternative Fuels: Start Small, Stay Flexible
Practical advice on adopting alternative fuels and ZEVs from HDT's 2026 Top Green Fleets, from renewable diesel and natural gas to electric trucks.
Read More →

