Chances are you have noticed the unusually shaped pieces extending out from the back end of a semitruck while driving down the road. These sections of metal, along with the thin flaps hanging between the tires, work together to foster increased efficiency in tractor trailers. Without these things, life on the road would be a total drag—literally.

Air Resistance, Drag, and Fuel Efficiency

A small, physics lesson for you: aerodynamic drag is created when the force that exists on any object resists its motion through a fluid. When this fluid is a gas, such as air, the resistance is referred to as aerodynamic drag. This air resistance pushes in the opposite direction of the motion of the object, which in this case is the tractor trailer.

The tractor trailers which transport over 70% of goods across the United States are notorious for using large amounts of fuel. As these trucks travel thousands of miles on our interstates, they push against the air and drag is created. This aerodynamic drag is produced as tractor trailers accelerate to 60+ miles per hour. The drag creates resistance causing the trucks to burn in excess of 50% of their fuel when they transport their goods across our nation. To counteract these levels of resistance, semitruck makers have engineered additions to the trailers which reduce resistance. One truck manufacturer has been able to increase fuel efficiency by 104%! This is fabulous news for trucking companies, drivers, managers, and environmentalists alike.

Tractor Trailer Aerodynamic Technology Used to Increase Efficiency 

In order to work with the natural physics of great speeds, engineers have created aerodynamic additions for the trucks which can reduce air resistance and increase fuel efficiency. Some of these additions, which are often seen on tractor trailers today, include:

Panels underneath the trucks

Referred to as skirts, these panels are added between the front and back sets of wheels. These skirts run the length of the trailer and reduce air flow around the undercarriage of the trailer. These measures increase fuel economy by 4-7%. The manufacturers fabricated skirts out of light-weight material such as aluminum, plastic, or fiberglass with plastic being the most resistant to damage from roadway impacts from debris and other materials.

Closing the gap

Several manufacturers have reduced resistance by as much as 6% through the creation of a device that completely covers the space between the tractor and the trailer. These gaps have often measured 18 inches or more. Thus, by covering this space with a large piece of plastic inserted between the sets of tires, fuel savings are increased by 2%.

Boat tails on the back

Lastly, boat tails, also known as rear fairing and trailer tails, have been added to semis. These are the extra flaps attached at the back end of a tractor trailer. These boat tails reduce turbulence behind the square rear end of the trailer. Boat tails are thin, collapsible pieces of plastic composite material which fold out from the rear of the trailer and are between 24-32 inches in length. The tails create a tapered shape from the air moving around the truck and can save more than 6% on fuel costs when traveling at speeds of 65 miles per hour.

Together, these fabrications reduce drag on the trucks by almost 20% percent, and trucking engineers continually work to create improvements utilizing current technology. Beyond the ones mentioned here, there are additional measures such as eliminating external mirrors in favor of using cameras throughout the semitruck. Another change which can improve fuel efficiency is the use of overall lighter materials when creating the trucks, such as carbon fiber and composites. These as well as adding an air dam, bumper closure, a hood-to-bumper fill, are making strides in manufacturing technology and the truck’s overall impacts to the environment.

Good News for Tractor Trailer Owners and Operators

With Amazon’s recent announcement of same-day and one-day shipping, the roads are only going to see increased traffic from logistical travel. The trucking industry is responding by continually working to advance technology to improve the number one transporter of products. Owners can take advantage of newer truck models that are much less expensive and cut down significantly on fuel consumption. Combining truck skirts, boat tails, and decreasing the gap between the tires can make the reduction in costs in your fleet or your individual tractor trailer.

Commercial Transportation Company in East Tennessee

At Roane Transportation, keeping our trucks on the road and continually working to improve the economy is our top priority. Serving East Tennessee and beyond we put drivers first and make getting them home a priority. Want to learn more about our company and its trucks? Are you interested in becoming a trucker with a company that prides itself upon getting truckers more home time as well as great benefits? Apply now or visit our website today for additional information on these topics and more.