U.S. diesel truck fleet emissions drop 30% over 5 years

The U.S. diesel-powered heavy truck fleet of about 3 million vehicles is now 30 percent cleaner in terms of emissions and more fuel efficient than it was five years, according to a recent study by the Diesel Technology Forum.    The U.S. diesel-powered heavy truck fleet of about 3 million vehicles is now 30 percent cleaner in terms of emissions and more fuel efficient than it was five years, according to a recent study by the Diesel Technology Forum.
   “Over a five-year period, the newest generation commercial vehicles have saved 4.2 billion gallons of diesel fuel, and reduced 43 million tons of carbon dioxide (CO2), 21 million tons of nitrogen oxides (NOx) and 1.2 million tons of particulate matter,” said Allen Schaeffer, the forum’s executive director, in a statement. 
   The forum hired technical research firm IHS Markit to conduct the study, which covered Class 3-8 diesel trucks manufactured from 2011 to 2016, and operating in all 50 states and the District of Columbia. 
   “California, which ranks 46th nationally with only about 25 percent of commercial trucks there equipped with the latest generation clean diesel technology could see substantial benefits for accelerated adoption of newer clean diesel technology trucks,” Schaeffer said.  
   “If California were to achieve the same new technology penetration as Indiana (51 percent), it can eliminate another 200,000 tons of NOx and 11,000 tons of fine particles that would bring cleaner air faster to all California communities than any other strategies,” he added.
   Since 2011, U.S. trucks reliant on diesel for their engine fuel have had to meet NOx emissions of no more than 0.2 grams per brake horse-power hour. This is in addition to particulate emissions levels of no more than 0.01 grams per brake horse-power hour set in 2007.
   The Diesel Technology Forum credited this dramatic shift in diesel emissions reduction to the truck and engine manufacturers’ collaboration with the Energy Department and the 21st Century Truck Partnership’s “Super Truck” program. 
   “While the intent of this valuable program is to push the margins of research engineering efficiency, it is clear that demand is leading many of these strategies to be integrated into the commercial truck fleet, contributing to real-world emissions reductions and fuel savings,” Schaeffer said.
   The forum noted that a Class 8 tractor-trailer powered by the latest generation diesel engine will save the operator 960 gallons of fuel annually. “When these benefits are compounded over the entire population of the clean diesel fleet, the 4.2 billion gallons of fuel saved between 2011 and 2016 is equivalent to almost 40 percent of the strategic petroleum reserve,” Schaeffer said.