Of the 11 million diesel vehicles over 10,000 lbs gross vehicle weight rating (class 3-8) in operation in 2018-2019, 43% were equipped with selective catalytic reduction (SCR) and particulate control technologies. In 2015, only one-quarter of the diesel vehicle population were similarly equipped. Since 2011, all new heavy-duty trucks were made with these technologies which reduce nitrogen oxide (NOx) emissions and particulate matter (PM).
Source: Diesel Technology Forum, 43 Percent of U.S. Commercial Trucks Now Powered By Newest-Generation Near-Zero Emissions Diesel Technology, Delivering Significant Emissions Reductions And Fuel Savings, Press Release, October 22, 2019. Based on data from IHS Markit.