STrucks and Aerodynamics

Posted by & filed under Parts Department, service, Trucker's Tips.

It is no secret that semi trucks run through fuel quickly. On average, a semi will get 6.5 gallons of  diesel per mile (naturally that number will fluctuate depending on semi model, going up hill, going downhill etc.). One way you can help with poor fuel mpg is aerodynamics.  Aerodynamics is defined by the Oxford Dictionary as “the study of the properties of moving air, and especially of the interaction between the air and solid bodies moving through it”. If you’ve ever driven a semi, then you know there is a whole lot of air moving around the outside of your truck that creates aerodynamic drag.

More specifically, there are four points around a semi that are affected by aerodynamic drag:

  1. The front of the truck.
  2. The gap between the truck and trailer.
  3. The sides of the trailer, including underneath the trailer.
  4. The back of the trailer.


There are ways you can combat aerodynamic drag in these areas by making sure truck and trailer are aerodynamically designed and by taking advantage of aerodynamic technologies that are available.


Aerodynamic design of a truck and trailer would include:

  • The front of the cab should be aerodynamically shaped with rounded edges.
  • A smooth transition between the top of the truck and trailer. The best would be to have the heights of the truck and trailer be the same.
  • The gap between the truck and trailer should be minimized as much as possible.
  • The underbody of the truck should be aerodynamically smooth and rounded.
  • Air should be blocked as much as possible from being able to travel underneath the truck.
  • Just like the front of the truck, the rear should be aerodynamically shaped with rounded edges.


Aerodynamic technologies that you could add onto your truck to help create a more aerodynamic rig are:


Nose Cone: A nose cone is installed to smooth the gap and airflow transition past the truck to the trailer.

Trailer Skirt: Trailer skirts are panels that are placed on the underside of a trailer to help reduce air from traveling under the trailer.  

Mud Flaps: Mud flaps that have slits or are ventilated and will allow air to flow through them will decrease drap.

Trailer Tail: Trailer tails are panels that are attached at the rear of the trailer to help redirect the airflow and create less wake.


The United States Environmental Protection Agency suggests that improving the aerodynamics of your truck and trailer could potentially improve your fuel economy up to 15% and save nearly you $4,000 in fuel costs. If your truck is lacking in any of the above listed aerodynamic recommendations, the cost savings alone should give you enough motivation to make changes to your rig.


North Dixie Truck and Trailer, Inc. can help you stay safe and save money by offering the best parts and services available. Whether it be an expert alignment, a thorough inspection or the top tires for the road, we’re a one-stop shop. And if you need an emergency pick-up, our 24-hour service is always there for you. Call us today at 419-221-2750 (Maintenance), 419-222-8785 (Parts) or 1-800-440-9523 (Emergency) or check us out online



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