A lack of trailer streamlining causes a partial vacuum to form at the rear of the trailer at highway speeds. This causes turbulent air in the form of large vertical (swirling motion) eddies to tumble into the partial vacuum and the large alternating (swirling motion) eddies cause the trailer to sway. Disturbances from passing vehicles or obstacles tend to amplify these (swirling motion) eddies and increase the trailer’s tendency to sway, increasing driver work load and fatigue, increasing drag and lowering fuel consumption. Streamlining the trailer by tapering consumption would be the best solution but is not practical due to a necessary reduction in trailer capacity and massive changes to loading facilities.
The large square area at the trailer rear causes a partial vacuum to form as the vehicle moves through the air at speed. These are usually devices that physically alter the trailer rear by using inflatable sails, fiberglass boat tails or rigid metal panels that extend to taper the trailer rear. However, these devices can be cumbersome, expensive, heavy and prone to collision damage. Physically tapering the trailer or load would be the best solution but is not feasible due to trailer capacity and loading operations.
Installation Instructions
EcoFins should be installed when vehicle is clean and skin temperatures are at or above +40F (+5C). The surfaces must be free of all contaminants. EcoFins should be installed on warm, clean, dry, flat surfaces. If a degreaser is used, it must be completely removed before installation. Regardless of the cleaning agent used, the final cleaning process should use a final cleaning agent such as rubbing alcohol or paint thinner. DO NOT USE any window cleaners containing ammonia. Use clean shop rags. For installation purposes, the cleaner, the dryer, the warmer, the better.
Location on Vehicles: EcoFins should be installed as close as possible to the back (trailing) edge of the vehicle. If the EcoFins must be moved forward to avoid rivet heads etc, keep the wide edges of the EcoFins within 12-18 inches (30-45cm) of the back for best performance. EcoFins are effective shielding gaps or reducing turbulence entering undesirable areas. Any vehicle component with an edge that is 90 degrees to the airflow is a possible EcoFins location provided that location receives an adequate supply of relatively undisturbed airflow. Examples: forward of wheel wells, hung tool boxes, trailer skirts etc. EcoFins are also effective on roof trailing edges of automobiles with a rear window slope exceeding 30 degrees. For ALL applications, ensure that the leading (wide) edge of the EcoFins is absolutely flush with the mounting surface.
Trailers: Place EcoFins forward of the rain ridge on the roof. CAUTION: Ensure trailer side EcoFins placement is adjusted so that when barn style trailer doors are opened, the doors and hinge bolts do not impact any EcoFins and cause damage.
Tractor: The ideal surface is flat but EcoFins can be installed on slightly curved surfaces as long as the leading edge is absolutely flush and the majority of the tape is in contact. If the pointed tip is slightly raised, it poses no performance degradation. Installation: Do not install on flexible side extender rubber strips, exhaust stacks, or heat shields.
Install EcoFins 3 per foot which is one every 4 inches on center. EcoFins are 4-1/2” long, 3-1/8” wide, and 1” high. (Metric: 12cm long, 8.2cm wide, 2.5cm high) Spacing is 4” (10.1cm) on center. Increase spacing to avoid rivet heads, lights, grab bars etc. Do NOT decrease spacing as this may decrease performance. Locate the vertical line where the leading (wide) edges of the EcoFins will be. Using duct tape, fasten the tape end to the top of the vehicle just forward of this line. Unwind the tape to the bottom of the vehicle. When the tape hangs absolutely vertically, secure the lower end with tape. Install the first EcoFins at the top at an appropriate inch mark. Continue every 4 inches until complete. The tape provides accurate spacing and a perfect straight edge. The warmer the surface temperature, the faster the tape will set.
If you have any questions you can contact us at 1 844 628 9059 between 8am and 5pm Mountain time or come by at 1030 East Commerce Drive, Suite 200, St. George, Utah 84790.