A friend recently asked me about semi trucks with the best MPG. I thought about it and said that while the make and model have a lot to do with impacting fuel efficiency, there isn’t one brand of semi truck that is the “best,” when it comes to MPG.
Now, while there are die-hard fans of every brand of semi that’s on the road, and some may dispute my conclusion, I think getting the best MPG from a semi truck has more to do with a combination of operator technique, the truck equipment and application of technology. Don’t get me wrong, today’s trucks are absolute marvels of engineering and new advancements and innovations occur at an unprecedented rate. But when it comes to fuel efficiency, it’s what you do to a truck, what you do with a truck and how you do it that makes all the difference.
Breaking the 10 MPG Barrier
In 1973, federal agencies estimated that semi trucks got 5.6 miles per gallon on average. Today, that number is around 6.5 miles per gallon on average. But remember, that’s on average. It’s been reported that some diesel semi trucks achieve 8 mpg or more.
In 2014, Cummins Inc and Peterbilt Motors Co. announced they had achieved 10.7 mpg with their Supertruck tractor-trailer demonstration.
“The goal of the SuperTruck program, initiated by the US Department of Energy (DOE), is to improve long-haul Class 8 vehicle freight efficiency. The program focuses on advanced and highly efficient engine systems and vehicle technologies that meet prevailing emissions and Class 8 tractor-trailer vehicle safety and regulatory requirements. In addition to the benefits of reduced fuel consumption and petroleum usage, the improvements in engine system efficiency will deliver a significant reduction in GHG emissions.”
Today, many drivers are taking advantage of modern advances in technology and engineering to hit and even surpass 10 miles per gallon with their rigs. But adoption of the new technology is key for seeing an increase in mpg across the board for the industry. Fortunately, more and more drivers and fleets are adopting the new technologies. In fact, the 2018 North American Council on Freight Efficiency’s (NACFE) 2018 annual fleet fuel economy study revealed that the new technology adoption rate had increased from 17% in 2003 to 44% in 2017.
10 Tips For Achieving 10+ MPG
The North American Council for Freight Efficiency “works to drive the development and adoption of efficiency enhancing, environmentally beneficial, and cost-effective technologies, services and methodologies in the North American freight industry.”
As part of their mission, NACFE partnered with the Rocky Mountain Institute to create Run on Less, an investigation of how employing new technologies, practices, and driver capabilities can enhance fuel economy. Their results for the 2017 Run on Less program “highlighted how drivers and fleets deliver high efficiency in the movement of goods in the long-haul segment of the trucking industry.”
Run on Less identified 10 actions that can help drivers and fleets attain 10+ miles per gallon with their trucks. Their recommendations include:
Use downsped powertrains and AMTs
Educate and incentivize conscientious drivers
Buy all available tractor aerodynamics
Adopt appropriate trailer aerodynamics
Optimize cruise control and vehicle speed
Keep equipment well maintained
Implement the right axle configuration
Embrace low rolling resistance tires
Provide tools to reduce idle time
Build a culture of methodically choosing technologies
Here are the full explanations of the Run on Less actions that play an essential role in helping achieve 10+ MPG:
Use Downsped Powertrains and AMTs – It is important to use automated manual transmissions that enable other technologies such as downspeeding. The duty cycle is key to these choices and, in particular with downspeeding, buyers should only apply the most aggressive downspeeding to tractors with high average speed (mph) where the amount of starts and stops are low.
Educate and Incentivize Conscientious Drivers. Run on Less benefited by having the trucks operated by some of the most proficient drivers on the road. Hiring, educating, and incentivizing drivers for the best fuel efficiency possible is a critical part of a successful fuel management system.
Buy All Available Tractor Aerodynamics. Fleets should start their specification process with all available sleeper tractor aerodynamics. NACFE has found that tractor aerodynamics have a very high ROI for line-haul applications, and fleets should only remove items if they suffer frequent damage in their specific operation.
Adopt Appropriate Trailer Aerodynamics. Fleets should address trailer aerodynamics in relation to the side, rear, and front (the tractor-to-trailer gap) and adopt the most appropriate technologies depending on routes, drivers, maneuverability, etc.
Optimize Cruise Control and Vehicle Speed. Fleets should maximize the parameter settings for cruise control to gain the most fuel savings. While a slower speed burns less fuel, there may be times when a faster speed can get a trucker more revenue. Thus, the conditions dictate whether it makes more sense economically to drive faster and burn more fuel.
Keep Equipment Well Maintained. The technologies employed on tractors and trailers work best when the trucks are well maintained. It is important to employ solid maintenance practices and utilize technology to help the equipment run as it is intended (e.g., automatic tire inflation on trailers, use of low-viscosity lubrication, alignment, replacing or cleaning all filters, etc.).
Implement the Right Axle Configuration. Fleets should use the correct axle configuration for the job, depending on the payload, speed, maneuverability, fleet practices such as tire management, and even resale value if the asset will be sold before its useful life is exhausted.
Embrace Low Rolling Resistance Tires. Low rolling resistance tires are critical for a fleet to get high mpg, but the most fuel-efficient tires are not right for every fleet, application, or region. A productive tire purchase and management process takes focus but will pay off.
Provide Tools to Reduce Idle Time. Drivers should shut the truck off whenever and wherever possible and use technology and engine parameter settings to reduce idle time.
Build a Culture of Methodically Choosing Technologies. Fleets should have a process to constantly monitor, adjust, and act upon new technology opportunities. Best practices include comprehensive understanding of the performance, either by testing or through industry involvement; robust payback or return on investment analyses; and supplier selection.
The results of the 2017 Run on Less investigation revealed an average 10.1 miles per gallon for the trucks involved. This proves that greater fuel economy for semi trucks is possible with the right technologies, techniques, and willingness to adopt and incorporate them into how you drive your truck.