Future of Off Highway Emissions Regulations
David Koberlein, Cummins' principal investigator for the Cummins-Peterbilt SuperTruck, shows off its fuel-efficient turbodiesel engine. "Cummins aims to boost heavy-duty diesel efficiency to 55%," SAE Off-Highway Engineering Magazine, November 16, 2015
The Future of Off-Highway Emissions Regulations

Jean L. Broge, Managing Editor of SAE award-winning mobility engineering magazines, discusses the latest emissions standards for medium-and heavy-duty vehicles.

In June, in a move that had been anticipated for some time, the U.S. EPA and the DOT’s NHTSA put on a united front with an announcement proposing national standards for medium- and heavy-duty vehicles that would “improve fuel efficiency and cut carbon pollution to reduce the impacts of climate change, while bolstering energy security and spurring manufacturing innovation.”

It’s well worth taking note of the announcement, for as Deutz’s Senior Vice President Georg Diderich points out in one of [the August 15 issue’s] feature articles, “The complicated future of off-highway engines” on page 10, what happens in on-highway emissions regulations will with little doubt eventually make it into off-highway.

Overall, it is expected that the proposed “Phase II” standards “will lower CO2 emissions by approximately 1 billion metric tons, cut fuel costs by about $170 billion, and reduce oil consumption by up to 1.8 billion barrels over the lifetime of the vehicles sold under the program.” According to EPA estimates, those reductions are nearly equal to the greenhouse gas (GHG) emissions associated with energy use by all U.S. residences in one year, with the total oil savings under the program greater than a year’s worth of OPEC imports.

With all the emissions and money being saved, “It’s good news all around,” said U.S Transportation Secretary Anthony Foxx. “Especially for anyone with an online shopping habit,” apparently a shout-out to acknowledge the vast amounts of goods being transported to eager consumers courtesy of the trucking industry and not a snide reference to any one particular consumer or hoarder with a shopping addiction.

By the EPA and DOT’s estimates, “the buyer of a new long-haul truck in 2027 would recoup the investment in fuel-efficient technology in less than two years.”

“With emission reductions weighing in at 1 billion tons, this proposal will save consumers, businesses, and truck owners money; and at the same time spur technology innovation and job-growth, while protecting Americans’ health and our environment over the long haul,” said EPA Administrator Gina McCarthy.

After “three years of extensive testing and research,” the proposed vehicle and engine performance standards would cover model years 2021-2027, and apply to semi-trucks, large pickup trucks and vans, and all types and sizes of buses and work trucks. They would achieve up to 24% lower CO2 emissions and fuel consumption than an equivalent tractor in 2018, based on the fully phased-in standards for the tractor alone in a tractor-trailer vehicle.

According to the agencies, the proposed standards are grounded in rigorous technical data and analysis and will allow manufacturers to rely on cost-effective technologies currently available or in development. They will not mandate the use of specific technologies, rather establish standards achievable through a range of technology options, and allow manufacturers to choose those technologies that work best for their products, including improved transmissions, engine combustion optimization, aerodynamic improvements, and low rolling resistance tires.

New for Phase 2 will be efficiency and GHG standards for trailers. The EPA trailer standards, which exclude certain categories such as mobile homes, would begin to take effect in model year 2018 for certain trailers, while NHTSA’s standards would be in effect as of 2021, with credits available for voluntary participation before then.

Medium- and heavy-duty vehicles currently account for about 20% of GHG emissions and oil use in the U.S. transportation sector, but only comprise about 5% of vehicles on the road. Globally, oil consumption and GHG emissions from heavy-duty vehicles are expected to surpass that of passenger vehicles by 2030.

It’s hard to imagine any powertrain engineer involved in any sector of the heavy-duty industry throwing papers from their desk into the air or a personal device into a wall in frustration upon hearing about the new standards, as their everyday focus is already, and has been for some time, on improving efficiencies and reducing emissions. We all know they are already in for the long haul.

Originally published as “EPA, DOT unload greenhouse gas and fuel efficiency standards” in Off-Highway Engineering Magazine, one of SAE’s award-winning publications, in August 2015 as an editorial by Jean L. Broge, SAE International’s Managing Editor.