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Trial over: California group says natural gas engines have proven their worth

The California Natural Gas Vehicle Partnership says near-zero emission engines are commercially viable for drayage work

Total Transportation Services is one of the companies that tested a near-zero emission engine from Cummins Westport on port operations during a pilot program. The California Natural Gas Vehicle Partnership says those engines are commercially viable for drayage work, successfully completing the test period. (Photo: Total Transportation Services)

Near-zero emission (NZE) natural gas trucks have been in operation in California ports for some time, but the vehicles have generally been operating under trial programs. According to the California Natural Gas Vehicle Partnership, that trial period is over – the trucks are ready for primetime.

The partnership announced this week that NZE trucks have proven they can handle the rigors of drayage work and as a result, have upgraded the technology to Technology Readiness Level (TRL) 9 in its Feasibility Assessment for Drayage Trucks report.

“In our experience, NZE natural gas trucks are the closest direct replacement for diesel trucks in terms of their power and speed, the 600-mile range they provide between refueling, the ability to fast-fuel in about 10 or 15 minutes, and most importantly, their ability to compete on a cost-per-mile basis,” Vic LaRosa, CEO and president of Total Transportation Services (TTSI), one of the test fleets, said. “Our fleet has been operating NZE natural gas trucks reliably and cost-effectively for several years and plans to continue our investment based on the proven results and [return on investment] we’ve achieved.”

The feasibility assessment was first published in March 2019 by the Ports of Los Angeles and Long Beach. The goal was to effectively evaluate zero-emission and NZE drayage trucks, as well as electric and other alternatively fueled vehicles, for operational suitability within the port environment. Each TRL indicates additional effectiveness. TRL 9 indicates the “actual system in its final form and operated under full range of operating mission conditions” is suitable for drayage applications.


The upgrade to TRL 9 for NZE engines is made in an addendum to the initial report. The update notes that “other parameters of infrastructure availability, economic workability and operational feasibility still remain to be fully addressed before ‘fully feasible’ can be assessed to near-zero natural gas trucks.”

The TRL 9 rating is limited to engine feasibility for drayage operations.

There were about 20 vehicles studied, all powered by the Cummins Westport ISX12N NZE engine. NFI, CR&R, Pacific 9 Transportation, 4Gen, Green Fleet Systems, and Orange Avenue Express joined TTSI in testing the vehicles over the past couple of years.

The ISX12N generates 400 horsepower and 1,450-pound feet of torque while reducing NOx emissions to 0.02 gram per brake horsepower-hour (bhp).  


The engines are designed for an 80,000-pound gross combined weight rating. During the test period, which ended on June 30, 2019, the trucks accumulated 567,603 miles with very few problems. The partnership said that updates to engine calibrations, replacing a crankcase breather motor, repair of valve stem seals and a replacing a spark plug coil were among the typical repairs needed. The NZE engines were available 98% of the time.

The trucks were not without a few issues, though.

“While not explicitly discussed in the demonstration report, drivers indicated that the trucks faced performance challenges on routes into the Central Valley and the High Desert, which may be linked to the hauling of heavy loads over the steep grades on Interstate 5 and Interstate 15 freeways,” the group said.

Since completing the official demonstration, the trucks have remained in operation and have now passed one million miles of operation, the California Natural Gas Vehicle Partnership said.

“The general technology is robust and well-proven, as evidenced by very strong commercial roll-outs by all of the mainstream heavy-duty truck OEMs [original equipment manufacturers],” the group said in an initial report in 2018, but noted that cost is a factor as there was only one NZE provider at the time and without competition, the incentive to drive down expenses was absent.

The demonstration program was led by Clean Energy and Cummins Westport and conducted under a grant provided by the California Energy Commission and the South Coast Air Quality Management District (SCAQMD).

“Cummins Westport is excited for the Ports of Los Angeles and Long Beach to officially recognize the commercial readiness of NZE natural gas trucks,” Gord Exel, president of Cummins Westport, said in a statement.

Exel said more than 100 NZE trucks are now operating in Southern California ports and “thousands” in trucking fleets throughout the country.


The group gathered with staff from SCAQMD to review the findings of the demonstration project, which was just released this week.

“It is SCAQMD staff’s opinion that the ISX12N is a fully commercial product in use in drayage,” it said, recommending that the NZE engines be raised to the TRL 9 level.

The Ports of Los Angeles and Long Beach handle approximately 40% of the nation’s total containerized import traffic, and 25% of total exports. The San Pedro Bay Ports’ Clean Truck Program has been working to improve the air quality of the ports and the surrounding communities through a number of demonstration programs and new-truck incentive offers.

More than 17,000 trucks operate daily in drayage operations in Southern California.

Cummins produces the NZE ISX12N in Jamestown, New York. The engine is offered on Class 8 vehicles from Freightliner, Kenworth, Mack, Peterbilt and Volvo.

Emissions are further reduced in California, experts said, due to the widespread use of renewable natural gas (RNG). More than 75% of the natural gas sold in California is RNG. 

Brian Straight

Brian Straight leads FreightWaves' Modern Shipper brand as Managing Editor. A journalism graduate of the University of Rhode Island, he has covered everything from a presidential election, to professional sports and Little League baseball, and for more than 10 years has covered trucking and logistics. Before joining FreightWaves, he was previously responsible for the editorial quality and production of Fleet Owner magazine and fleetowner.com. Brian lives in Connecticut with his wife and two kids and spends his time coaching his son’s baseball team, golfing with his daughter, and pursuing his never-ending quest to become a professional bowler. You can reach him at [email protected].