Recent headlines tout the new interest in hydrogen for heavy-duty commercial trucks from some leading manufacturers. Traveling the roads in America today, over 90 percent of commercial vehicles are powered by diesel technology. Fast forward twenty years from now, and trucks will most likely be powered by a diversity of fuels and technology. Some may be powered by hydrogen and fuel cells, some may be battery electric, some may be operating on renewable natural gas or renewable diesel fuel. In any event, according to many sources, rather than having a “sell by“ date, diesel will remain as the dominant technology moving the nation’s freight for decades to come.

A variety of analysts and researchers have explored the future trucking fleet composition, and by 2040, diesel is projected to still dominate the Class 8 truck fleet.

  • Bloomberg New Energy Finance, that traditionally publishes an upbeat forecast for electrified cars and trucks, estimates that only 19 percent of the heavy-duty commercial truck fleet in the U.S. will be electrified by 2040 – making 81 percent of heavy-duty trucks powered mostly by diesel and some natural gas.
  • IHS Markit estimates that 80 percent of commercial truck sales in the U.S. will be powered by diesel by 2040.
  • The Fuels Institute estimates that, under aggressive uptake of zero-emissions technology in commercial vehicles, diesel will make up 65 percent of heavy-duty truck sales and 86 percent of the fleet by 2040.
  • The International Council on Clean Transportation notes that there is only one manufacturer of a zero-emissions Class 7 and 8 truck available in the marketplace today, albeit with limited range, while others are still in pre-production phase. ICCT notes that heavy duty zero-emissions trucks will overtake diesel in sales over the next two decades.

All of these statements are forecasts each with considerable assumptions about new technology success in the commercial marketplace, price and availability of both diesel and new alternative fuels, and many other factors. In the meantime, progress in reducing emissions, fuel consumption and greenhouse gas emissions from diesel technology continues with new milestones now well established in the future – good news for climate and clean air .

Much like passenger vehicles, commercial vehicles are now subject to stringent fuel economy and greenhouse gas emissions standards that have been phased in since 2014 and more stringent rules kicking in in 2021 – just a few months from now. Over the lifetime of these rules, more efficient trucks will have eliminated more than 1 billion tons of greenhouse gas emissions between 2014 and 2027. While there will be emerging zero-emissions trucks for sure, they will be in fractional percentages of the total fleet market, making the majority of the benefits delivered by trucks fueled by diesel.

Much more efficient diesel trucks are already generating big fuel savings and climate benefits. According to Fleet Advantage, a business consultancy that measures real world fuel economy, a new Class 8 tractor has a 15 percent fuel economy benefit over a similar 2016 model. This is a substantial benefit that translates directly to greenhouse gas emissions and as more older diesel trucks are replaced with new, we can expect these benefits to continue to grow.

While truck, engine and component makers are working to achieve the next level of greenhouse gas emissions reductions and reducing fuel consumption, they are also committed to reducing emissions from the current generation of diesel even closer to zero. U.S. EPA’s Cleaner Trucks Initiative, when proposed in 2021 is expected to establish new goals to further lower emissions of oxides of nitrogen (NOx), a smog forming compound, along with other provisions in the coming years.

Diesel trucks also have the capability of operating on advanced renewable biofuels that drive down greenhouse gas emissions, operating on high quality blends of biodiesel or 100 percent renewable diesel fuel. These are fuels that have at least a 50 percent reduction in greenhouse gas emissions relative to petroleum, with renewable diesel fuel, GHG emissions are reduced by at least 80 percent. Many fleets are using the fuels today, and in response, a number of leading oil companies announced the planned retooling of petroleum refineries to produce new supplies of renewable diesel fuel. If planned capacity for the fuel equates to actual production, these facilities have the capability to displace all of the petroleum diesel fuel consumed in California.

Recent headlines on any new technologies – fuels, new model cars and trucks or just consumer products – are eye-catching and interesting. Often however they leave out an important part of the story… in this case that diesel technology will continue to dominate the industry and that it will have even nearer-to-zero emissions with lower GHG emissions as well . These benefits will be vital in the next several decades before alternative fuel vehicle and infrastructure availability arrives at an impactful scale.