TrailerTails: A tale of tech timing

There are no sure things with technology. Companies can have innovative patents, positive media coverage, devoted loyal customers, and yet never live up to market goals.

Some case studies are easy to spot on the road. Consider ATDynamics’ TrailerTails. Introduced commercially in 2008, at one point in time these innovative aerodynamic solutions were headed towards 10%+ of new trailer market share. All four Department of Energy SuperTruck I prototypes by Peterbilt/Cummins, Daimler, Volvo and Navistar relied on them to exceed 10 mpg in 2014 through 2016. Their patented origami folding system was difficult to improve on and definitely beneficial.

The principles of trailer boattails are well researched in full scale testing going back to the 1930s,  scale model wind tunnels going back to before the 1960s, and competent CFD analytical studies dating from the 2000s. I did extensive evaluations in wind tunnel, in CFD and on the road in my past work and met many other researchers over the years working on boattails. NACFE has written about them in our Confidence Report Trailer Aerodynamics, released in 2016 and recently updated. The published research shows the longer the tail, the better the drag reduction. The maximum legal length is 60 inches, but ATDynamics limited the extension to what reasonably could fold up on the back of the trailer, essentially the width of one trailer door.

Stemco acquired ATDynamics in 2015 and added TrailerTails to its catalog. The market looked promising. Fuel efficiency focused customers like MVT, Prime, C.R. England and others promoted TrailerTails, putting them on a sizeable number of trailers. A 2014 American Trucking Associations Technology & Maintenance Council announcement estimated more than 50 fleets had deployed TrailerTrails, 50,000 were on order and an estimated 200,000 would be on the road by 2017. CCJ reported an interview from the 2015 Mid-America Trucking that more than 40,000 TrailerTails were in use with 500 customers.

TrailerTails are great drag reducers. No argument there. Paired with skirts and tractor-trailer gap reducers, the SuperTrucks exceeded 50% drag reductions versus their Model Year 2009 baselines. The U.S. SmartWay program lists them as verified aerodynamic devices capable of 9% fuel economy improvement combined with skirts.

Last year Stemco ceased sales of TrailerTails. What happened? Stemco determined that TrailerTails did not fit well with its product line. I can speculate on additional contributing factors.

Operationally, my findings over the years in following multiple variations of boattails is that the longer the tail and the more manual the operation, driver acceptance is more challenging.

A fleet manager once summed it up to me that the kiss of death for a technology starts with a designer saying, “All the driver has to do is…” His experience was that any additional steps required of the driver were challenging to implement with 100% reliability. Not a reflection on drivers, but on the need to automate. The manual nature of stowing and deploying the tails clearly impacted driver acceptance and use.

The inability of the driver to see the TrailerTail when deployed also led to at least a few damaged light poles at truck stops and other yard issues. Mike Roeth, NACFE’s executive director, and I both drive a lot of highway miles. A game we developed was to spot how many TrailerTrails were not deployed.

Improvements were made to the design, but TrailerTails we’re also fighting an unexpected extended drop in fuel prices. Beginning in January 2015, national diesel fuel prices dropped and stayed below $3 per gallon for three full years, crossing back above $3 in January 2018, according to DOE’s Energy Information Agency.  It then dropped again below $3 per gallon in January 2020 and stayed there through March 2021.

TrailerTails were interesting to the market with fuel hovering near $4 per gallon and projected to increase in the future. When it fell and stayed below $3 fleets prioritized investments elsewhere, namely other efficiency opportunities like better tractors.

During this same period (2015-2021), OEMs – empowered by both the success of DOE SuperTruck I and II programs and ever more stringent EPA/NHTSA GHG emissions reductions – launched updated and improved aerodynamic tractor models.

As fuel prices now again spike toward the $4 range, it will be interesting to see if those fuel prices will stabilize and if a next generation of TrailerTails will reenter the market to compete with a range of alternative boattail systems.

The point is that new technologies are never sure things. Much depends on factors beyond the control of the technology. Having great patents, great customers, big orders, government support and positive media splash are not always enough to ensure success. 

Rick Mihelic is NACFE’s Director of Emerging Technologies. He has authored for NACFE four Guidance Reports on electric and alternative fuel medium- and heavy-duty trucks and several Confidence Reports on Determining Efficiency, Tractor and Trailer Aerodynamics, Two Truck Platooning, and authored special studies on Regional Haul, Defining Production and Intentional Pairing of tractor trailers.