Nearly half the commercial trucks operating in EPA Regions 9 and 10 are now powered by the newest-generation of Near-Zero Emissions diesel engines, according to Diesel Technology Forum ‘s analysis of 2020 U.S. vehicles in operation data (Class 3-8) provided by IHS Markit.
Analysis: Clean Diesel Truck Adoptions Jumping in Southwest, Northwest
Nearly half the commercial trucks operating in EPA Regions 9 and 10 are now powered by the newest-generation of Near-Zero Emissions diesel engines, according to analysis by the Diesel Technology Forum.

Nationwide, the newest near-zero-emissions diesel trucks now make up almost half of the more than 11 million diesel-powered commercial vehicles on U.S. roads
Image: Diesel Technology Forum
Those two EPA regions take in the entire Southwest and Northwest as well as Hawaii and Alaska. Now standing at exactly 43.3%, the share of new technology diesel trucks in the regions expanded by 6.6% between July 2019 and December 2020.
Nevada and Washington both saw a 19% increase in the number of new technology diesel trucks in operation in their states. California saw a 17% increase in the number of new technology diesels in operation compared to 2019.
Diesel Technology Forum pointed out that beginning in 2010, all new heavy-duty trucks have been equipped with selective catalytic reduction (SCR) and particulate control technologies. DTF said these combine to achieve stringent Environmental Protection Agency emissions requirements for nitrogen oxide (NOx) emissions of no more than 0.20 grams per brake horsepower hour (g/BHP-hr). This is in addition to particulate matter (PM) emissions levels of no more than 0.01 g/BHP-hr.
Almost 50% nationwide
Nationwide, the newest, cleanest, near-zero-emissions diesel truck technologies now make up almost half of the more than 11 million diesel-powered commercial vehicles on U.S. roads, per the DTF analysis.
Since 2007, these newest-generation diesel trucks have eliminated 202 million tons of carbon dioxide (CO2), 27 million tons of NOx, and saved almost 20 billion gallons of diesel and 472 million barrels of crude oil. “Put into context,” DTF said in a press release, “the emissions and fuel savings attributable to new-generation diesel engines in commercial trucks equates to making 43 million cars all-electric or creating 42,000 wind turbines on land five times the size of Washington, DC.”
DTF also noted that by 2030, thanks to the continued increase of newest-generation diesel-powered vehicles, these savings are projected to grow to 1.3 billion tons of CO2, 47 million tons of NOx, 2.7 million tons of PM, 130 billion gallons of diesel, and 3.1 billion barrels of crude oil.
According to Vehicles in Operation Data (2019-2020) from IHS Markit, a total of 15 states are at or above the national average for the percentage of clean diesel Class 3-8 commercial vehicles (all U.S.: 49%) while 23 states are growing their clean diesel fleets faster than the national average (all U.S.: 6.3%) A full state-by-state breakdown is available on the DTF website: https://www.dieselforum.org/in-your-state.
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