Are you worried about your car having a low gas mileage? Now think about a freight truck - which weighs about 10x a normal car, hovers at about 4-7 mpg and clocks in 80,000-100,000 miles. Per year. That truck's fuel budget is about $58k per year, and its carbon footprint is 148 metric tons of CO2 per year. When we multiply these numbers by 2 million, the number of tractor-trailers in the US, we quickly realize that improving efficiency for trucks, no matter how small, can have a major financial and environmental impact.
Hayward, CA-based ATDynamics recognized the potential to improve efficiency for the large truck fleet in the US, and developed the TrailerTail®, an aerodynamic tail system that can easily be installed on existing trucks and instantly improve fuel efficiency by reducing drag.
In other words, the conventional truck design is simply not aerodynamic.
As shown in the image, drag is derived from the front of the tractor, the gap between the tractor and the trailer, the underbody of the trailer, and the rear of the trailer.
ATDynamic's flagship product, the TailerTrail, reduces drag at the rear of the trailer by over 12%, leading to a 6.6% fuel-efficiency gain at 65 mpg, and 9-12% gain wehen combined with the Transtex skirt (for reducing underside drag).
A mere 6.6% improvement may not seem substantial, but when considering the design constraint to develop a technology for existing trucks (that require certain dimensions to carry standard containers) and the sheer numbers mentioned above, this 6.6% can lead to impressive results: savings of ~$2900 and ~7.4 metric tons of CO2 per year per truck, or considering the total fleet in the US of 2 million trucks, a potential saving of $6.6 billion and 14 million tons of CO2 per year in the US alone.
The TrailerTail, estimated to cost about $2200, will pay for itself within a year. Moreover, the TrailerTail is cleverly designed to be easily installed in one hour, and if needed, the tail closes automatically or manually in less than 4 seconds.
ATDynamics' TrailerTail is commercialized and receiving positive feedback from its clients. "The TrailerTail was the best investment in fuel economy I have ever made", Brett Tobin Trucking. ATDynamics is also working with truck manufacturers to improve aerodynamics of future designs - a critical need for an industry which accounts for 26% of fuel used for transportation in the US.
Also, check out 17-year-old's Jonny Cohen's GreenShields project which similarly improves fuel efficiency by reducing drag, aimed specifically at school buses.