Heavy-duty truckers use several tactics to limit their diesel use and improve fuel efficiency — making their equipment more effective, training their drivers — but turning to alternative fuels usually isn’t one of them.
That’s the conclusion of a survey of nearly 100 fleet managers surveyed by the nonprofit American Transportation Research Institute and the University of Michigan Transportation Research Institute. The survey was funded by oil giant ExxonMobil.
In a Monday report — featuring insights from companies that collectively represent more than 114,500 heavy-duty truck tractors and 350,000 trailers — researchers probed the industry’s relationship with fuel-saving technologies and alternative fuels.
Every fleet included in the survey uses diesel. The fuel tends to be a major expense for truckers — a median of 24 percent of total operating costs — as well as one of the most toxic sources of pollution.
Last year, truckers hauled 70 percent of all freight moved in the U.S., or 10 billion tons, with volumes expected to increase by 17 percent over the next decade, according to the report. The average fleet in the survey hauls 2.1 million tons of cargo some ten million miles annually with a median fuel economy of 6.5 miles per gallon, according to the report.
The average passenger vehicle in the U.S. gets roughly 25 miles per gallon.
As a whole, the trucking industry consumed 54 billion gallons of fuel last year, including 39 billion gallons of diesel. More than half of fleet managers told researchers that their vehicles sometimes idle in traffic congestion. Also common: frequent stopping and starting, inching along at low speeds and engines idling overnight, spewing out fumes.
But cleaner options aren’t popular with truckers. Managers complained that many alternative fuels are rarely available, lack a wide-reaching distribution infrastructure and a mature market to drive down costs. They also worried that cleaner fuel might not actually improve fuel economy.
Alternative energy adopters lean toward biodiesel blends such as B5, B10 and B20. But nearly 78 percent of survey respondents said they would never use gasoline, 71 percent swore off dimethyl ether or hydrogen fuel cells and nearly 65 percent refused to consider electric trucks.
Only 4.4 percent of fleet managers reported using hybrid electric drive, while just 1.1 percent said their vehicles include hydraulic hybrid engines.
While advocacy groups such as the nonprofit Environmental and Energy Study Institute say that electrification and alternative fuels are gaining traction, “increasing the fleet’s energy efficiency remains critical.”
“Increasing vehicle fuel efficiency is a cost-effective way to significantly lower the transportation sector’s emissions and reduce vehicle lifecycle cost without requiring major infrastructure adaptations,” the group said on its website.
Monday’s report found that trucking companies tend to scale back diesel use by opting for speed limiters, adaptive cruise control and “eco-driving” training in tractors. More than nine in ten companies use lighter aluminum wheels. Some three quarters rely on tires with low resistance to rolling.
“Further implementation and development of these technologies will likely help improve heavy-duty fleet efficiency,” said Brandon Schoettle, lead author of the report at University of Michigan.
Tire pressure monitoring and automatic inflation are also common, as are side skirts to reduce drag. But fewer than half of managers said they use automatic engine starting and stopping mechanisms, battery-powered air conditioning and heating units, downsized engines and driver incentives for improved fuel economy.
Larger companies are more patient when trying of fuel-saving strategies or switching to alternative fuels. Smaller fleets — which make up the vast majority of the industry — are less inclined to change without rising diesel prices or a quick return on their investment, researchers found.
But soon, truckers may have no choice but to adapt. In August, the U.S. Environmental Protection Agency and the National Highway Traffic Safety Administration finalized the so-called Phase Two fuel efficiency and emissions standards for medium- and heavy-duty vehicles.
The government expects the mandate to shave 1.1 billion metric tons of carbon dioxide emissions. But nearly all fleet managers told researchers that they expect the regulations to inflate costs related to operations and new truck purchasing.
Plunging oil prices this year means that “the economic case for natural gas has taken a significant hit,” as has the financial rationale for using electrification or hybridization, said David W. Cooke, senior vehicles analyst with the Union of Concerned Scientists.
“However, we are seeing some uptake as costs for those systems come down, and many fleets have demo fleets testing some of this technology out,” he said.
But trucks last a long time, so updated vehicles will only be gradually put into rotation.
“And with a growing economy, these improvements in efficiency are more like treading water in terms of the overall fuel use and emissions from the fleet,” Cooke said. “Additional policies or technology breakthroughs will be needed to make a significant dent in emissions from the heavy-duty sector before 2030.”