By Kent Smerdon, Airtab
Vehicle aerodynamic drag has two constants: it is undefeatable and it costs you money. The North American trucking industry has two constants: trailers load from the rear and drivers accidentally collide with docks. Two more constants: tractor OEMs keep touting their slick new aero friendly designs, but trailers, their big butt ends being the biggest drag culprits of all, are virtually ignored.
If fuel and performance issues claim top of mind in the industry, why do companies, even members of the coveted Top 100 lists, consistently fail to address this critical drag region when a proven cost effective drag reduction solution exists?
Aero drag has another constant: drag increases as the square of the vehicle airspeed – everywhere, not just at the front. This is aerodynamic law – not a suggestion. A truck driving 60 mph (speedometer) with a 30 mph tail wind has an aero drag of “x”. Turn that truck around, drive the same speed into the now 30 mph head wind and the drag skyrockets to 9 times x! – including the suction drag at the trailer doors. There’s more. The more aerodynamically efficient the tractor is, the higher the airspeed reaching the trailer doors. That means higher suction drag at that location even at the same speed. Put another way, since vehicle drag is cumulative – the more aero attention paid to the front of the rig, the more attention must be paid to the rear if total drag reduction is the goal. Why is this part of the vehicle still ignored?
After-market rear mounted devices that physically alter the shape of the trailer are proven but can be problematic. One is applicable to side loading trailers only. Another, applicable for use on rear loaders, is heavy, prone to snow accumulation, relatively expensive to purchase and install yielding longer ROI times. They can be complex devices requiring maintenance, driver “participation” to deploy and stow, (or through use of expensive complex auto deploy systems) and are liable to collision damage and repair revenue loss via yard manoeuvering mishaps or loading dock/trailer door contact.
A simple low cost wind tunnel proven solution for drag reduction at vehicle rears has been on the market for over twenty years and sold worldwide. It mounts on the sides and top of tractors and trailers, not on rear surfaces, weighs about four pounds per unit, is maintenance free and will deliver fuel savings in the 3% to 5% range when both tractor and trailer are fitted. It offers vehicle stability improvements increasing safety, reducing driver stress and fatigue. It provides spray suppression benefits improving visibility in rain for all road users. They work constantly whenever the truck is at speed, not just when deployed.
It is the Airtab® vortex generator, visit www.airtab.com. ROI for long haul ops is 60 to 90 days. As Kevin Rutherford once said, “Airtabs are a no-brainer for any truck operation.” Follow us on Facebook #airtabfuelsavers.
Visit us at Booth 68232, West Wing Mid-America Trucking Show in Louisville, KY, March 22-24, 2018.☚