Regular preventive maintenance on heavy trucks can increase fuel economy up to 10%, says the latest confidence report from Trucking Efficiency, a joint operation of the North American Council for Freight Efficiency and Carbon War Room. The reports analyze and confirm the effectiveness of certain components and practices that can positively affect fleet operations.

“Fleets need to maintain their vehicles to ensure safe and reliable performance, avoid costly breakdowns, and allow the vehicles to reach their maximum useful life,” said the group’s statement, issued on Dec. 15. “However, even a vehicle that is running safely and reliably can achieve fuel economy savings thanks to additional or better-optimized maintenance.”

Trucking Efficiency explored the link between maintenance practices and fuel economy. A study team found that the industry is aware of the impact poor maintenance has on fuel economy but is unable to quantify it, and therefore avoids investments that would improve the maintenance process.

Yet the team found that fleets that implemented rigorous PM programs saw fuel consumption improvements in the 5% to 10% range. 

The report said there are 10 areas where proper and consistent maintenance should be directed:

• Lubricants and engine oil

• Intake and exhaust systems and diesel particulate filters

• Engine cooling system

• Air compressor

• Wheel alignment

• Tires

• Fuel filters

• Aerodynamic devices

• Electrical systems

• Air conditioning systems

“There was a definite benefit to fuel economy” with proper preventive maintenance, said Mike Roeth, NACFE’s executive director. “It’s generally believed that there’s not a definite benefit that you can put your thumb on, but it’s important enough that we felt it was worth putting out the report.”

The researchers asked fleet managers what they have seen on how maintenance affects fuel economy. Some said weather, geography and operations affected it. But there also were maintenance problems – filters that were plugged or loose and tires that were underinflated, among others, Roeth related. Correcting those conditions sometimes yielded more than a 10% betterment in economy.

“A lot of these things have been around forever,” he continued. “On diesel particulate filter cleaning, manufacturers are at a quarter-million miles and others lower” as recommended service intervals.

For example, “Cleaning DPFs sooner sometimes gained 1.5% or 2% in economy. It’s different for different manufacturers, and of course the duty cycle,” highway routes versus routes that cover more local running, he said. The group plans to delve into the DPF subject more thoroughly.

The report said that good PM practices also keep trucks in top shape, which can raise resale values; build morale and improve safety for drivers; and reduce equipment-related citations and CSA demerits. It also said that predictive maintenance through data analysis and telematics holds promise in reliability and uptime. 

“It’s going to come at a cost, but will save fuel and increase reliability,” Roeth said of making repairs before a component fails unexpectedly, sometimes with costly results. “To me, there’s roadside breakdowns and repairs, then there’s preventive maintenance. A lot of people don’t buy into it, but then they hear examples and they say, ‘Hey, maybe it does make a difference.’”

The Trucking Efficiency group is considering a road show that would showcase fleets that are achieving high fuel economy in everyday operations. If it’s feasible, the “run on less” tour might happen next fall.