To truly maximize your profit margins, you need to address aerodynamic drag. By equipping your semi-trailers with advanced aerodynamic kits, you can smooth out airflow, reduce the “effective wind resistance area,” and significantly increase overall fuel economy (MPG). Here are the most effective technologies available today:
1. Aerodynamic Side Skirts
Trailer side skirts are panels that hang on both sides of the chassis, bridging the gap between the landing gear and the rear wheels. Their primary function is to prevent wind from rushing underneath the trailer, where it hits the axles and creates turbulence.
According to the NACFE (North American Council for Freight Efficiency), side skirts are the industry’s most widely adopted drag-reducing device. The data is compelling:
- Function: Directs air along the sides rather than underneath.
- Savings: Provides fuel savings of 1% to over 5% compared to standard trailers.
2. Trailer Boat Tails (Rear Fairings)
The rear of a square trailer creates a massive low-pressure vacuum zone (often called “suction drag”) that pulls the vehicle backward. Rear fairings, commonly known in the industry as “Boat Tails,” are designed to solve this.
While traditional collapsible panels can sometimes interfere with door operations, modern designs have evolved. An aerodynamic Trailer Tail tapers the airflow at the rear, minimizing the vacuum effect.
Testing by the ATA (American Trucking Associations) highlights the efficiency of these devices:
- Design: Directs airflow inward at the rear to reduce suction.
- Efficiency: High-quality rear aerodynamic systems can offer potential fuel savings ranging from 5% to 15% under optimal highway conditions.
3. Nose Cones & Gap Fairings
The open space between the truck cab (tractor) and the trailer face is an aerodynamic nightmare. Air gets trapped here, hitting the flat front of the trailer and causing significant drag.
Installing a Nose Cone or a Gap Fairing creates a bridge for the air to flow smoothly from the truck cab over the trailer roof. This ensures a seamless transition and reduces turbulence.
NACFE studies indicate that optimizing this gap can result in:
- Smoother Transition: Prevents air from hitting the trailer’s “headboard.”
- Savings: Typical fuel consumption reduction of 1% to 2%.
4. Vented Aerodynamic Fenders
Traditional solid mud flaps protect vehicles from debris, but their flat, rectangular design acts like a parachute, trapping wind and increasing drag.
Vented Fenders (or aerodynamic mud flaps) solve this by allowing air to pass through the slats while still catching water and mud spray. A study by Exa Corporation demonstrated that vented designs can improve fuel economy by approximately 2.7% by simply reducing the drag coefficient.
Conclusion: Which Device is Most Effective?
There is no single “magic bullet,” but the concept of “Audience Stacking” (combining multiple devices) yields the best results. While side skirts are the most common starting point, combining them with a boat tail and gap fairing maximizes efficiency.
Industry data suggests that a fully aerodynamically optimized trailer can achieve fuel savings of over 10%. With environmental regulations (like EPA SmartWay) becoming stricter, equipping your fleet with these devices is not just about saving money today—it’s about future-proofing your business.
Interested in customizing an aerodynamic trailer for your fleet? Contact KALES Vehicle today for a consultation.
