Fort Wayne, Ind. — The persistent industry view that “we were done with aero 10 years ago” is wrong, as the North American Council for Freight Efficiency (NACFE) discovered while researching its latest report “An In-depth Look at Tractor & Trailer Aerodynamics.”
Today aerodynamics is being looked at from a systems perspective with the tractor and the trailer considered as a unit. Recognizing this when updating its Tractor Aerodynamic Confidence Report and Trailer Aerodynamic Confidence Report, the NACFE has chosen to publish one report that combines tractor and trailer aerodynamics.
“Our second report on aerodynamics in 2020 told fleets that good aero was worth doing,” said Mike Roeth, NACFE’s executive director. “Six years of data did not change that conclusion. It strengthened it. What changed is that the devices got more durable and the business case got better.”
On the tractor side the report covers aerodynamic configurations across the sleeper and day cab markets, including aero sleepers, partial aero sleepers, classic sleepers, aero day cabs and classic day cabs. On the trailer side it covers side skirts, rear devices, underbody and wheel devices, nose cones and front fairings, and combination systems.
The Impact of Aerodynamics
The report includes information on fleet adoption patterns, the economics of investing in aerodynamic devices and the current regulatory and policy landscape. The report not only looks at aerodynamics on diesel-powered vehicles but also explores the surrounding aerodynamics for compressed natural gas (CNG), and zero-emission powertrains.
It also includes separate Confidence Ratings for tractor and trailer aerodynamic technologies that are based on how fast the technology pays back and how confidence the data makes NACFE in that payback number.
Fleet Recommendations
The report includes recommendations for fleets, OEMs/device manufacturers and for policy makers, standard bodies and researchers.
The first move for fleets depends on what they pull and where they are in their aerodynamic journey.
- For dry vans and refrigerated vans, the order is skirts first, gap management second and rear devices last.
- Manage the tractor-trailer gap next.
- Treat rear-of-trailer devices as the last move, and only after verifying a maintenance plan and the fleet’s dock-and-yard damage exposure.
- On weight-sensitive trailers, added aerodynamic hardware competes with revenue payload, so a device that pays on a van can cost a bulk hauler money.
- These weight sensitive fleets should start with aerodynamic mud flaps. After mud flaps, look to chassis-specific treatments in the underbody and impingement area where the geometry allows.
- Start with the OEM aerodynamic base model. Stripping the aerodynamic features off an aerodynamic base model costs about 10% in fuel economy, and the base model costs almost nothing over a non-aero spec.
- Layer day cab aerodynamics on regional tractors, where the benefit is real and still underused.
- For natural gas trucks, spec from the top of the aerodynamic menu to offset that penalty.
“The report found that aerodynamic technology is both proven and under-adopted,” said Dean Bushey, NACFE’s director of programs. “One thing we do know is that aerodynamics is not a finished subject. There is more to come.”
Click here to download the report.
Dana Guthrie is an award-winning journalist who has been featured in multiple newspapers, books and magazines across the globe.
