Of the 11 million diesel-powered commercial (Class 3-8) vehicles on the road, 43% are now using cleaner burning technology, including selective catalytic reduction (SCR) and particulate control, according to new research from the Diesel Technology Forum (DTF).

While SCR was first introduced in 2007, it became mandated equipment for heavy-duty trucks in 2011. Along with particulate control technologies, these combine to achieve U.S. Environmental Protection Agency emissions requirements for nitrogen oxides 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.

Since the introduction of SCR, diesel-powered commercial vehicles haven't emitted 126 million tonnes of carbon dioxide, 18 million tonnes of NOx, and 1 million tonnes of PM. The technologies have also saved 12.4 billion gallons of diesel and 296 million barrels of crude oil, according to DTF's projections.

Commercial trucks with these technologies increased 6.8% from December 2017 to July. There are now 4.5 million such vehicles in Class 3 through Class 8 on the road.

"As more of America’s commercial trucks rely on the newest, cleanest diesel technologies, greater air quality and fuel savings benefits are being realized by communities across the country," said Allen Schaeffer, executive director of the forum.