In comments submitted to the U.S. House of Representatives Transportation and Infrastructure Committee, the Diesel Technology Forum outlined the leading role played by diesel engines in global commerce across all sectors. Thanks to a fundamental transformation in environmental performance, the Forum further outlined how the technology achieves levels of near zero emissions, and how it will continue to be a dominant technology in the future for moving freight.

“Our goods movement industry can’t move without diesel technology. The fleet of trucks, trains, marine vessels and cargo handling equipment rely largely on diesel engines to move goods from factory floors, to warehouses and our doorsteps. The latest generation diesel technologies are now far more efficient and fundamentally cleaner while the manufacture and maintenance of diesel engines, and the vehicles and equipment they power, are drivers of employment and economic growth,” said Allen Schaeffer, executive director of the Diesel Technology Forum. DTF is a not-for-profit educational organization dedicated to raising awareness about the importance of diesel engines and the latest generations of advanced diesel technologies and fuels.

“Whether by land, sea, road or rail, diesel engines are the prime mover of the global economy, powering over 95 percent of all marine workboats and vessels, over 95 percent of heavy-duty commercial vehicles, 100 percent of freight rail, and a substantial percentage of supporting materials handling equipment. Because of a unique combination of features, including the most energy efficient internal combustion engine, power density and performance in moving heavy loads, durability and reliability, global availability of fuels and servicing, diesel engines are the undisputed technology of choice for moving goods today.

“Over the last two decades, investments in the newest generation of advanced diesel engines and cleaner, low-sulfur diesel fuels have enabled our economy to expand, while also dramatically reducing emissions from highway freight transport. In long-haul trucking, diesel technology dominates, powering 97 percent of Class 8 big-rig trucks in the United States. New technology diesel engines, in everything from the smallest commercial trucks to railroad locomotives to the largest marine workboats, now achieve near-zero emissions performance. Coupled with the ability to utilize a wide range of renewable low-carbon biodiesel fuels as well as suitability for hybridization and electrified components, diesel technology is ensured a key role in the future of moving goods.”

As the Committee examines the economic, environmental and societal impacts of freight transport consider the following:

  • Diesel is an Economic Driver: Diesel engines and the vehicles and equipment they power are directly responsible for supporting $12 billion in economic activity in the first quarter of 2019, or about 12 percent of all private sector economic activity. Without diesel trucks and equipment, we could not generate the $1.2 billion in economic activity provided by the warehousing and logistics sector. According to research commissioned by the Diesel Technology Forum, industries that produce diesel technology and use these technologies generate $275 billion in economic activity.
  • Diesel is a U.S. Manufacturing and Skilled Workforce Success Story: Over 1 million heavy-duty diesel engines were manufactured in facilities in 13 states across the U.S last year. It takes a highly skilled workforce to produce these engines and an even larger workforce to keep these engines running. The Department of Labor estimates that more than 265,000 Americans are employed as truck, bus and diesel engine specialists. Diesel mechanics are employed in a growth industry, as the Department of Labor predicts that the industry will expand by five percent each year.
  • The U.S. is a Global Leader in the Production of High-Quality, Low-Sulfur Diesel Fuels: Since 2010, all diesel engines in the U.S., both on-road and off-road, have been utilizing low-sulfur diesel fuels that enable the use of advanced emissions control technology systems (selective catalytic reduction utilizing diesel exhaust fluid) and particulate filters that working together, virtually eliminate emissions from diesel engines. Thanks to newfound sources of domestic energy, diesel fuel is the leading finished petroleum product exported abroad. U.S. refiners sent 470 million barrels of diesel fuel abroad in 2018 helping to fulfill overseas demand.
  • New Technology Diesel Engines Deliver Clean Air Benefits Today: According to the latest information, 43 percent of the U.S. commercial truck fleet in operation on our roads today is of the newest generation clean diesel power that achieves near-zero emissions. These new technology diesel engines have eliminated more than 26 million tons of nitrogen oxides (NOx) already since 2010. New diesel trucks are so clean that it would take more than 60 new-generation diesel trucks to equal the emissions from one truck sold in 1988.
  • New Technology Efficient Diesel Engines Are Delivering Major Greenhouse Gas (CO2) Reductions Today: More efficient diesel trucks now on the road since 2010 have already saved 12 billion gallons of fuel and eliminated 126 million tons of greenhouse gas emissions between 2011 and 2018. This is equivalent to taking 26 million cars off the road for a year.


The U.S. Environmental Protection Agency (EPA) and National Highway Traffic Safety Administration (NHTSA) estimate that the Commercial Vehicle Fuel Economy and Greenhouse Gas Reduction Standards Phase 1 rules saved 270 million tons of CO2 and 530 million barrels of oil between 2014 and 2018, and that the Phase 2 rules will save another one billion tons of CO2 and nearly two billion barrels of oil between 2021 and 2027. Research commissioned by the Diesel Technology Forum confirms that the majority of these significant benefits will be delivered by more efficient diesel trucks. These benefits are enormous, and they will be largely generated by diesel technology, as 80 percent of truck sales by 2030 will still be diesel. These more efficient trucks will have eliminated the same emissions as taking just about every car off U.S. roads for a year.

  • Use of Advanced Renewable low-carbon Biodiesel Fuels Enhances Diesel: More and more fleets are making the switch to advanced biofuels including renewable diesel fuel and biodiesel fuel. These fuels are considered advanced biofuels by U.S. EPA capable of reducing greenhouse gas emissions by at least 50 percent. In California, where the use of these fuels is growing quickly, biodiesel and renewable diesel fuel have provided the greatest reduction in greenhouse gas emissions, according to the California Air Resources Board. These significant benefits could not be realized without the diesel engine.


There are significant opportunities for rapidly reducing emissions of criteria pollutants (nitrogen oxides and particulate matter) through strategies to accelerate the turnover from older technology to new technology, particularly in the marine, rail and trucking sectors. For example, replacing a single older marine workboat engine in the ports of Houston, Baltimore or New York can reduce emissions of nitrogen oxides by 30 tons of NOx per year, an amount equivalent to removing over 26,000 cars for a year.

While new fuels and technologies for freight movement are emerging, diesel engines, particularly in the largest trucks, are expected to continue to dominate the sector well beyond the 2030 timeframe. Truck and engine manufacturers are continuing now to reduce emissions from diesel engines. Further progress for lower emissions is on the horizon, as truck and engine manufacturers are engaged with the U.S. EPA and the California Air Resources Board on the Clean Truck Initiative, developing tomorrow’s generation of diesel engines.

From coupling with hybrid-electric technology and battery-storage systems, to pushing thermal efficiency boundaries, to advanced waste-heat recovery systems, to utilizing high-quality advanced renewable biodiesel fuels, new-generation advanced diesel technology will continue to be a dominant technology for commercial trucking and other goods movement sectors and help achieve clean air and climate goals for a sustainable future.