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.
