Smarter Trucking Saves Fuel Over the Long Haul

Tags: Trucking

Photograph by John Eastcott and Yva Momatiuk, National Geographic

On-board technology tools help trucking companies boost fuel economy by monitoring and controlling what goes on behind the wheel.

More than 33 years ago, 33 truckers competed in a fuel economy contest dubbed the "Double Nickel Challenge." Named after radio slang for the 55-mile-per-hour (mph) speed limit then in force in the United States, the goal was simple: to test the claim—common among truckers at the time— that big rigs got better mileage at higher speeds.

Long-haul truckers from all over the United States gathered in East Liberty, Ohio, to watch as drivers navigated laps around a track, first at 55 mph, and then at any speed of their choosing. With a few exceptions, the trucks burned less fuel in the first, speed-limited trial.

More than three decades later, the double-nickel U.S. speed limit enacted in the wake of the 1973 Arab oil embargo has faded into history on most highways. But so has credibility for the claim that higher truck speeds beget better fuel economy.

In fact, road-speed governors—electronic engine controls that limit driver speed—are standard equipment on modern 18-wheelers. In Europe, all trucks have their road-speed governors set by the factory to a specified value determined by law. In the United States, vehicle owners decide the setting, but most large fleet operators electronically limit their drivers to between 60 and 63 mph, with some flexibility to accelerate when needed. Safety is one consideration, but the other aim is fuel cost savings.

Yet both the trucking industry and policy makers are convinced that more can be done to curb the growing amount of fuel burned by big rigs hauling goods around the country.

In August 2011, the U.S. government announced its first fuel economy standards for heavy-duty vehicles, with the goal of requiring big tractor-trailers to achieve 20 percent better mileage by 2018. Europe is also working on a framework for limiting trucking fuel consumption and carbon emissions. And Japan, where trucks are estimated to be responsible for 25 percent of automotive greenhouse gas emissions, set standards to improve trucking fuel performance in 2006.

Changes in truck aerodynamics, mass reduction, and improved rolling resistance are all strategies that could yield significant fuel economy improvements, according to a U.S. National Academy of Sciences (NAS) report issued in 2010. Perhaps even more valuable are "intelligent vehicle" systems, which can reduce the amount of fuel trucks burn by encouraging driver behavior changes that have long been known to save fuel.

Go Slow to Save Dough

Curbing driver speed is the most widely recognized behavioral change that can save fuel, with the 60 to 65 mph range the sweet spot for many 18-wheelers on today's highways, says Glen Kedzie, vice president of environmental affairs for the American Trucking Associations, a trade group headquartered in Arlington, Va.

On average, a truck traveling at 65 mph instead of 75 mph will experience up to 27-percent improvement in fuel consumption. "As a rule of thumb, for every one mile per hour increase in speed, there is a corresponding 0.14 mile-per-gallon (mpg) fuel consumption penalty," says Kedzie.

Operating at even lower speeds (around the old double-nickel limit, for example) would further reduce aerodynamic drag and decrease fuel consumption, but safety risks increase if trucks travel much slower than cars. And the problem voiced by truckers during the days of the Double Nickel Challenge—that slower speeds translate to less income—remains today.

In the United States, Australia, Canada, and Europe, for example, Hours of Service regulations force truckers to rest after a certain number of hours on the road.

"With these restrictions, some trucks traveling at 55 mph may not be able to get their loads to their destinations on time," Kedzie explains.

Fortunately, the tool kit for eking out extra miles per gallon has expanded far beyond driving speed. In an era of more intelligent and connected vehicles, trucking technology for better fuel economy now includes wireless sensors, GPS chips, algorithms, and sophisticated real-time data analysis.

Fleet operators can collect highly detailed information about a given driver and vehicle, for example. "They get a nearly real-time report on specific drivers," Kedzie says. "It includes where drivers stopped, how long they rested, how often they braked or hard-braked, and the engine temperature."

It might sound like Big Brother has moved into the trucking industry, but analyzing this data and training drivers accordingly can translate to real savings.

"Between the worst driver and the best, the difference in fuel economy can reach 25 percent," says Michael Roeth, executive director of the North American Council for Freight Efficiency.

Others cite more modest gains from technology designed to encourage fuel-efficient driving behavior. For example, GreenRoad, a driver performance and safety management firm based in Redwood City, Calif., reports that drivers using its real-time feedback system consistently cut fuel and maintenance costs by 10 percent.

"Between the worst truck driver and the best, the difference in fuel economy can reach 25 percent."— Michael Roeth, executive director, North American Council for Freight Efficiency

Oil and gas company Shell claims its FuelSave Partner system for commercial trucks can also improve fuel economy by 10 percent. The Shell system collects information on 13 separate driver behaviors, such as hard-braking and excessive engine revving, and creates weekly or monthly emissions, fuel, and efficiency data reports for fleet managers.

Tractor-trailers in the United States currently average just six mpg. But some fleets can achieve up to 8.5 mpg, with the most efficient trucks reaching 10.5 mpg.

"If we could bring the average up to the best real-world experience today, incredible cost would come out of freight," says Roeth. At current diesel fuel prices, each one-percent fuel economy improvement saves about $900 per truck annually.

A Trucking Transition

The tipping point doesn't seem far off. "The nation's truck fleet is as old as it has ever been," says Roeth. That's because, in hard economic times, fleet operators are keeping trucks longer. But new purchases can be postponed for only so long, and an influx of new trucks will hit U.S. highways within the next few years, according to Roeth.

It's an opportune time for the recently finalized fuel economy standards in the United States, where liquid fuel consumption by medium- and heavy-duty vehicles represents 26 percent of all transportation fuels burned. Trucking fuel consumption has increased more rapidly—in both absolute and percentage terms—than consumption by passenger vehicles.

A projected 628,000 Class 8 trucks (the heaviest trucks on the road, including big rigs) will be produced in North America in 2012 and 2013, according to commercial vehicle industry analysis firm ACT Research. This figure includes an estimated 45,000 trucks to be exported to countries including Australia, South Africa, and Russia.

"This estimate is nearly the total of all trucks built from 2007 to 2010," Roeth notes. "It is crucial these trucks include fuel economy features."

Increased truck production is not just a North American trend. ACT also reports increases in Europe and China, where heavy-duty truck purchases jumped to more than 1.1 million in 2010, from 200,000 in 2001.

"Trucking is a deeply cyclical industry—either feast or famine," says ACT President Kenny Vieth. In 2006, for example, North America produced more than 375,000 heavy trucks, about 40,000 more than ACT predicts for 2013. Strong growth in heavy-duty truck production over the next two years would make up for the profoundly weak market of the past few years.

As hundreds of thousands of new trucks begin moving the world's freight during the next two years, it's crucial that fuel efficiency per ton of freight improve, says Roeth. "Increasing ton-miles per gallon delivers the best result," he explains. "Pickup trucks can get 20 miles per gallon, but we don't want 60 pickups hauling what one tractor-trailer can haul."

Keeping Up with The Changes

The drive to use technology for improved big rig fuel economy reflects several fundamental changes in the business of moving freight by truck, from new emission standards to rising fuel prices.

"In 20 years, the government has issued five versions of pollutant emission standards," says Roeth. Scrubbing systems and other equipment required under those regulations tend to add weight to trucks.

In general, trucks are getting heavier. "But the overall weight limit hasn't changed," Roeth notes. Trucks need to be able to haul more weight using smaller engines and fuel tanks.

Fuel Tools Deliver Savings

"Our customers are looking for every opportunity to save fuel," says Peter Adams, program manager for Smart Transport at Shell Global. Shell hopes its subscription-based FuelSave system will increase loyalty among commercial truckers.

"If we help our customers manage their fuel effectively, they remain profitable, stay in business, and keep buying fuel," says Adams.

One customer in the Netherlands, for example, has piloted the Shell FuelSave Partner system on 17 trucks in its recycling division. Logistics service provider Emons Group's 450 trucks, which haul chemicals, glass, and other cargo, consume nearly four million gallons of fuel annually.

Fuel alone accounts for about one-quarter of Emons' operating costs, so the FuelSave pilot's results were encouraging. The 17 trucks using the Shell system for six months dropped fuel consumption by an average of 5.3 percent, with some individual drivers achieving 10-percent savings.

New innovations promise even bigger savings on the horizon. "The sky's the limit as to what technology can provide," Kedzie says.

It's becoming possible, for example, for a truck to be programmed to shift at just the right time for maximum fuel efficiency and minimum wear and tear. Braking can be automated, with the proper distance calculated based on road conditions, weather, and load weight. Other systems use retinal observation to detect signs of driver fatigue.

"Trucks are becoming more intelligent," Kedzie notes, "which will result in the industry becoming safer, more fuel efficient, and more productive."