Study: Propane Terminal Tractors vs. Diesel
Find out what researchers found when they collected emissions data from a MAFI-manufactured propane terminal tractor and Tier 4 diesel technologies.

Recent research results confirmed the propane-powered tractor yielded 99% fewer nitrogen oxide (NOx) composite and idle emissions than either diesel tractor tested.
Photo: Port Newark Container Terminal
New data released from the Propane Education & Research Council (PERC) and Port Newark Container Terminal (PNCT) shows propane-powered terminal tractors are significantly cleaner than their diesel-fueled counterparts in several key emissions reduction areas.
In recent testing at PNCT, researchers collected emissions data from a MAFI-manufactured propane terminal tractor and Tier 4 diesel technologies.
Data Says it All: Propane or Diesel for Terminal Tractors?
The results confirm the propane-powered tractor yielded 99% fewer nitrogen oxide (NOx) composite and idle emissions than either diesel tractor. Additionally, the compared with diesel tractors, the propane tractor produced:
77.5% fewer THC idle emissions.
14% fewer brake-specific carbon dioxide emissions.
75% fewer TPM emissions.
MAFI’s propane tractor is powered by Power Solutions International’s (PSI) 8.8L propane engine, which is over 90% cleaner than mandated U.S. Environmental Protection Agency (EPA) standards. In addition, the engine is certified to the optional ultra-low NOx emissions standard as defined by the California Air Resources Board (CARB) for heavy-duty engines with .02 grams of per brake horsepower.
Plus, the propane engine competes with diesel engines on performance, providing 270 horsepower with 565 lb.-ft. of torque.
“This near-zero emissions technology terminal tractor is available now for an affordable price,” said Gavin Hale, vice president of business development at PERC. “Propane technology adoptions are continuing to grow at ports, terminals, and warehouses throughout the country to eliminate diesel emissions and make significant strides toward greenhouse gas reduction.”
Not only are propane-powered terminal tractors cost effective, there is also grant money available through the Diesel Emissions Reduction Act (DERA) to support the transition to clean propane-powered fleet technology. This includes terminal tractors, propane autogas fleet vehicles, and energy production technology.
More Green Fleet

Samsung SDI Takes Full Control of GM Battery JV as Indiana Plant Pivots to Energy Storage
Samsung SDI is taking full control of its Indiana battery plant with GM, marking a major shift from the EV-focused joint venture Charged Fleet first covered in 2023.
Read More →
NWSA Taps CALSTART to Administer Zero-Emission Drayage Assistance Program
CALSTART will provide free technical assistance services to drayage fleets serving the Ports of Seattle and Tacoma and looking to transition to cleaner technologies and help decarbonize freight hubs.
Read More →
EV Fleet Reality Check: What Operators Wish They Knew Before Electrifying Their Work Vans
Electric work truck upfits bring new compatibility questions. Learn how parts availability, OEM guidance, power demands, and route planning can affect fleet performance.
Read More →
Peterbilt Expands Sourcewell Partnership with Electric Vehicle Lineup
Peterbilt Motors Company’s cooperative purchasing agreement with Sourcewell and its Canadian partner, Canoe Procurement Group, now includes including Peterbilt's battery-electric vehicle lineup.
Read More →
WTC Group Expands Sustainable Operations with Kalmar Ottawa T2 EV Fleet
Commercial adoption of the Kalmar Ottawa T2 EV terminal tractor continues to grow as customers add the zero-emission yard tractor to their fleets. WTC Group has placed an order for a Kalmar Ottawa T2 EV.
Read More →
Where Propane Autogas Fits in Today's Fleet Fuel Strategy
Learn more from PERC's Joel Stutheit, as he explains why propane autogas remains a practical alternative for fleets seeking to reduce emissions without sacrificing operational flexibility.
Read More →
Schneider Electric Simplifies Commercial EV Charging with New Charge Pro for the U.S.
Schneider Electric’s updated Charge Pro Level 2 chargers deliver reliable, flexible charging for multi-unit dwellings, fleets and workplaces, as well as public and destination charging locations such as hotels and retail centers.
Read More →
ChargePoint and Onvo Expand Highway Fast Charging Across the Northeastern U.S.
ChargePoint is working with Onvo, a locally owned travel plaza brand headquartered in Pennsylvania, to install ultra-fast EV charging stations at locations in the Northeastern U.S.
Read More →
The City of Kingston Celebrates Purchase of 2 Mack LR Electric Refuse Trucks
The City of Kingston, Ontario, Canada, a municipality with a vision of being “Canada’s Most Sustainable City,” recently showcased two Mack LR Electric refuse trucks following their successful deployment in 2025.
Read More →

