Report recommends ways to improve, regulate fuel economy of heavy vehicles

  • 08-Sep-2010 01:24 EDT
Dr. Brown.jpg

“Our message to the federal government is don’t institute standards [for medium- and heavy-duty vehicles] too quickly; you don’t know enough [yet] to be able to do it smartly. The industry is willing to work with you,” said Dr. Andrew Brown Jr., chair of the committee that wrote the National Research Council report, and the 2010 President of SAE International.

“This is very timely,” Dr. Andrew Brown Jr., Executive Director and Chief Technologist for Delphi Corp., stressed at SAE International World Headquarters during his presentation of the National Research Council (NRC) report “Assessment of Fuel Economy Technologies for Medium and Heavy Duty Vehicles,” for which he served as committee chair.

He summarized many of the congressionally mandated report’s 27 major findings and 12 major recommendations for SAE employees just days after President Barack Obama instructed the U.S. EPA and NHTSA (National Highway Traffic Safety Administration) to develop new federal standards governing fuel consumption and greenhouse-gas emissions of medium- and heavy-duty vehicles, to take effect beginning with the 2014 model year.

Brown, the 2010 President of SAE International, presented the report’s findings and recommendations for attendees of the SAE Commercial Vehicle Engineering Congress (ComVEC) on Oct. 5.

“Model year 2014 is basically September of 2013,” Brown pointed out. “In terms of getting any regulations done and getting that built into the process, getting it legislated, approved, etc., it’s very tight.”

Currently, there are no fuel-consumption standards for tractor-trailers, transit buses, work trucks, and other such vehicles, which account for about 26% of the transportation fuel used in the U.S., according to NRC.

“There are technologies out there today and expected in the next five years that can help achieve what the president said was a 25% fuel-consumption reduction. That’s his aim; I think it’s achievable,” said Brown. These technologies include hybrid powertrains, clean diesel technology, improved aerodynamics, low rolling resistance tires, and lightweight designs.

“On the powertrain side, you can get a fuel-consumption reduction by as much as 50%. On the vehicle technology side, you can get a reduction in fuel consumption by as much as 15%. The key thing is that not all of these technologies have the same impacts nor do they have the same impacts on all types of vehicle.”

For example, the biggest benefit comes from hybridization of powertrains, Brown noted. “So why don’t we just hybridize all trucks? You can’t do that because of the duty cycle,” he said. “If I put hybrid technology on a tractor-trailer at 60 mph on the highway, it’s only going to get me at most 10% [fuel-consumption reduction] or maybe nothing at all. But if I put that hybrid technology on a garbage truck with stop-and-go patterns, I can get pretty close to that 50%. The difference is all in the duty cycle.”

The committee not only evaluated the technology side of the equation, Brown explained, but also the socioeconomic side to evaluate the impact on society, including “unintended behaviors and consequences” such as pre-buys, where vehicles are purchased in advance of upcoming regulations. Other aspects considered include rate of replacement of older vehicles and ton-miles shipped related to cost of shipping.

“If you get a lot of people doing a pre-buy, you won’t see the fuel-consumption reduction that you thought you might,” he said. “Before you set your regulatory framework, you better do your homework to really understand what these implications are.”

So who should be regulated? The committee recommends the final-stage vehicle manufacturers, not the component makers. And it recommends regulating all classes of vehicles because of unintended consequences if just the “heavy hitters” are targeted.

“These guys in Class 8 are smart, too,” Brown said. “They know if there’s a regulation that’s going to require me to invest more dollars—which I don’t really have an incentive to do except to save some oil—here’s what I’ll do: I’ll move into Class 7 vehicles that are not regulated. So instead of having one Class 8 tractor on the road, I’m now going to have two Class 7s on the road, and I’m going to consume more fuel, generate more CO2, etc.

“So we told the government you cannot exempt certain classes of vehicles, at least initially,” though ambulances and smaller school buses are examples of some vehicles that could be exempt, he added.

In setting fuel-consumption standards, regulators should use a measure that accounts for the amount of freight or passengers carried by these vehicles, such as gallons per ton-mile, the report says: The miles-per-gallon measure used to regulate the fuel economy of light-duty vehicles is not appropriate. For example, a partially loaded tractor-trailer could travel more miles per gallon than a fully loaded one, but this would not accurately measure the fuel efficiency of moving goods.

The report does not recommend a specific numerical standard; NHTSA needs to establish standards tied to the task associated with a particular type of vehicle. NHTSA should base its regulations on national data on the average payload carried by each vehicle type, the report says.

“Our key recommendation from all of this study and work is that the federal government should perform a pilot program,” Brown said, “whereby they set a regulatory framework and then engage fleets of vehicles from all around the country, and actually evaluate the performance of those vehicles…and collect real-world information to determine if in fact they achieved the benefits that they were pursuing.”

“It’s going to take a collaborative effort between government, industry, and government labs to do this right,” he added. “They shouldn’t just arbitrarily set those standards, which has been done on the light-duty side over the years [and] has led to adversarial relationships. We don’t need to do that here.”

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