The introduction of new technology clean diesel truck engines and emissions control systems into Pennsylvania’s trucking fleet over the last five years is now at a 35% level, yielding significant emission reductions and substantial fuel savings, according to new research commissioned by the Diesel Technology Forum (DTF).


“Almost 3 million heavy-duty diesel commercial vehicles introduced in the U.S. from 2011 through 2016 now on the road powered by the latest generation clean diesel engines, and these trucks have delivered important benefits in the form of cleaner air, fewer carbon dioxide (CO2) emissions and dramatic fuel savings. Over a five-year period, the newest generation of commercial vehicles have saved 4.2 billion gallons of diesel fuel, and reduced 43 million tonnes of CO2, 21 million tonnes of oxides of nitrogen (NOx) and 1.2 million tonnes of particulate matter,” said Allen Schaeffer, Executive Director of the Diesel Technology Forum.


“Because diesel overwhelmingly dominates the heavy-duty truck sector and is also the number one power source for medium-duty vehicles, the transition to newer generations of clean diesel technology (model years [MY] 2011 and later) is significant,” Schaeffer continued. “The 30% national average is up from just 25.7% last year. The research also estimated that significant further benefits will accrue to communities across the country as more of these newer generation clean diesel trucks enter into service.


Pennsylvania, with 35% of commercial trucks equipped with the latest generation of clean diesel technology, ranks sixth and exceeds the national average adoption rate of 30%. These new technology clean diesel trucks have saved 222 million gallons of diesel fuel, resulting in 2.2 million fewer tons of C02 while slashing 900,000 tons of NOx emissions. If the penetration rate of new technology clean diesel trucks in Pennsylvania were to accelerate to that of leading states (Indiana, 51%), an additional 34 million gallons of fuel and 340,000 tons of greenhouse gas emissions could be saved while eliminating an additional 46,000 tons of oxides NOx. Getting more clean diesel trucks on the road will bring cleaner air faster to all Pennsylvania communities than any other strategies,” said Schaeffer.


The benefits research was conducted by IHS Markit, a global technical marketing research firm. State rankings data is based on DTF analysis of IHS vehicles in operation data representing Class 3 – 8 diesel trucks from MY 2011 through 2016 in all 50 states and the District of Columbia through December 31, 2016.


“The U.S. trucking fleet is transitioning to newer clean diesel technology, which means immediate fuel savings, lower greenhouse gas emissions and cleaner air. This newest generation of clean diesel trucks have NOx emissions that are 99% lower than previous generations, along with 98% fewer emissions of particulate matter, resulting in significant clean air benefits throughout the U.S. Beginning in 2011, all heavy-duty diesel trucks sold had to meet NOx emissions of no more than 0.20 grams per brake horse-power hour (g/BHP-hr). This is in addition to particulate emissions levels of no more than 0.01 grams per brake horse-power hour (g/HP-hr) established in 2007.


“Achieving these substantial emissions reductions and efficiency advancements was in part the result of collaboration of the nation’s leading truck and engine manufacturers working with the Department of Energy (DOE) and the 21st Century Truck Partnership’s “Super Truck” program,” said Schaeffer. “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 and contributing to real-world emissions reductions and fuel savings.”



“In addition to these substantial societal benefits, a Class 8 tractor-trailer sized vehicle powered by the latest generation clean diesel engine will save the owner 960 gallons of fuel each year, relative to the previous generation of technology. 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% of the strategic petroleum reserve,” Schaeffer concluded.


How Do Newer Diesels Achieve Near-Zero-Emission Levels?

To achieve these new levels of emissions and efficiency performance, the new clean diesel system relies on an efficient engine and optimized combustion system utilizing the most advanced fuel-injection, turbocharging and engine management strategies coupled with advanced emissions controls and after-treatment technologies, including particulate filters and selective catalytic reduction (SCR) systems, all running on ultra-low-sulfur diesel (ULSD) fuel.


The Diesel Technology Forum is a non-profit organization dedicated to raising awareness about the importance of diesel engines, fuel and technology.