Related: CNG: From an Idea to a Solution
Researchers to Develop Low-NOx NG Engines for California
UK-based Ricardo Inc. says it will partner with the Gas Technology Institute to design the engines to emit fewer NOx emissions while powering medium-duty commercial vehicles.

A pair of private research organizations will develop natural gas engines as viable, fuel-efficient and less polluting alternatives to diesels for use in California. UK-based Ricardo Inc. says it will partner with the Gas Technology Institute (GTI) to design the engines to emit fewer oxides of nitrogen while powering medium-duty commercial vehicles.
Two Ricardo-GTI projects, co-funded by Southern California Gas Co., will aim to reduce NOx emissions from truck engines, helping attain NOx emission levels that surpass California Air Resources Board’s goals, consume less fuel than current diesels, and provide higher engine performance with the current reliability, a Recardo announcement said.
In one project, Ricardo will support development and testing of advanced ignition systems – high frequency discharge and pulsed nano plasma – as part of GTI’s collaboration with the California Energy Commission. Ricardo will test the systems so their effect on engine performance can be measured and evaluated.
In addition to Ricardo and SoCalGas, GTI’s other partners on this project include Power Solutions International, Inc. and EnerPulse Technologies Inc.
In the second project, sponsored by the South Coast Air Quality Management District,.Ricardo and GTI will develop an ultra-low emission natural gas engine for on-road Class 4-7 medium-duty trucks.
These diesel trrucks are currently among the top 10 sources of NOx emissions in California’s South Coast Air Basin, authorities say, and are projected to remain one of the largest, even as older and higher polluting trucks are replaced by vehicles meeting 2010 emissions standards.
The aim is to meet federal ambient air quality standards in coming years, the announcement said. Such ultra-low emission natural gas engines would cut NOx by 90% compared to now. They would approach levels from equivalent all-electric vehicles, when the emissions associated with electricity production are taken into account.
“Medium and heavy-duty trucks are an essential part of the transportation mix in California,” said Ricardo’s president, Clive Wotton, “but they are also significant contributors to total NOx emissions. Trucks such as these are not as amenable to the type of electrification and hybridization approaches that have been applied very successfully in the passenger car and SUV sector.
“However,” he said, “the substitution of diesel with natural gas as a transportation fuel for these classes of vehicle offers some attractive potential benefits in reducing NOx emissions.”
In addition to Ricardo and SoCalGas, GTI’s other partners on this project include Power Solutions International, Inc. and EnerPulse Technologies Inc.
More Fuel Smarts

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 →
Kempower Adds Flex EV Charger to Help Support Transition to Megawatt Charging
The Kempower Mega Satellite Flex has both a CCS and MCS connector, allowing operators to serve both types of heavy-duty vehicles.
Read More →
Hino Adds Electric Class 6/7 Truck
Hino says the Le Series is an important step in the company's efforts to reduce environmental impact and support its customers’ sustainability goals.
Read More →
Can Multi-Speed EV Transmissions Solve Heavy Trucking’s Biggest Electric-Vehicle Problems?
A startup called Sigma Powertrain believes purpose-built multi-speed gearboxes can boost efficiency, reduce battery size and improve gradeability for heavy-duty battery-electric trucks.
Read More →
Hendrickson Debuts Electraax E-Axle for Medium-Duty Trucks
Developed with Driventic, Hendrickson's new integrated e-axle is designed to improve efficiency, reduce weight, and extend range in Class 6-7 EV applications.
Read More →
50 Ways Fleets Can Cut Fuel Costs Now — Without Buying New Trucks
Fuel savings don’t come from one big change. They come from dozens of small ones. Here’s how leading fleets are stacking gains across drivers, routing, maintenance, and more.
Read More →
Top Green Fleets 2026: How Fleets Are Reducing Emissions in the Real World
What works in sustainable trucking today? Heavy Duty Trucking's Top Green Fleets are finding practical ways to cut fuel use, reduce emissions, and keep freight moving.
Read More →
