I saw this article in Science Daily: Low-Drag Trucks: Aerodynamic Improvements & Flow Control System Boost Fuel Efficiency In Heavy Trucks It details how simple changes to the shape of existing long haul trucks can improve fuel effiency 6-7%. Installation of pneumatic devices could also add another 5% savings and may make handling semis safer for all on the road, too. I'm looking forward to seeing these one the road. The fuel savings is significant, the article details that 1% change in fuel efficiency for all trucks can save 200,000,000 gallons of fuel a year! "The aerodynamic improvements produced by geometry changes – which generate fuel savings of as much as six to seven percent -- involve rounding aft trailer corners, installing fairings and making other changes that smooth air flow over the boxy trailers. Fuel savings of an additional five percent come from pneumatic devices that blow air from slots at the rear of the trailer to further improve and prevent separation of air flow."
