Study: Propane Terminal Tractors Up to 99% Cleaner Than Diesel

A propane-powered terminal tractor. Photo via Propane Education & Research Council.

New data released from the Propane Education & Research Council (PERC) and Port Newark Container Terminal (PNCT) in mid-May contends that propane-powered terminal tractors are significantly cleaner than their diesel counterparts in several key emissions reduction areas.

In recent testing at the Washington, DC-based PNCT, researchers collected emissions data from a propane terminal tractor built by German manufacturer MAFI and Tier 4 diesel technologies. The results confirm the propane-powered tractor yielded 99% fewer nitrogen oxide (NOx) composite and idle emissions than either diesel tractor.

Additionally, PERC said, the propane tractor produced 77.5% fewer THC idle emissions, 14% fewer brake-specific carbon dioxide emissions and 75% fewer TPM emissions than the diesel tractors.

MAFI’s propane tractor is powered by Power Solutions International’s (PSI) 8.8-liter propane engine, which is more than 90% cleaner than mandated U.S. Environmental Protection Agency standards and certified to the optional ultra-low NOx emissions standard as defined by the California Air Resources Board for heavy-duty engines with .02 grams of per brake horsepower.

Plus, the propane engine competes with diesel engines in terms of performance, providing 270 horsepower with 565 lb.-ft. of torque.

“This near-zero emissions technology terminal tractor is available now for an affordable price,” PERC Vice President of Business Development Gavin Hale said. “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 to support the transition to clean propane-powered fleet technology,” PERC said in a statement. “This includes terminal tractors, propane autogas (liquefied petroleum gas) fleet vehicles and energy production technology.”

More about propane-powered terminal tractors is available at