How Trucking Companies And Manufacturers Are Increasing Fuel Efficiency In Semi Trucks

Semi trucks drive approximately 140 billion miles per year, transporting and delivering 68 percent of all goods in the United States. The United States used over 39 million gallons of diesel fuel in 2011, so it is no wonder the EPA wants large truck manufacturers to improve gas mileage by 10 to 20 percent between 2014 and 2018. Here are several ways semi truck manufacturers and trucking companies are making changes to improve their semi truck's gas mileage.

Tire Rolling Resistance

Tire rolling resistance is the third-largest factor affecting a vehicle's fuel economy. Thirteen percent of a truck's fuel costs are consumed by overcoming tire rolling resistance. Trucking companies can control the amount of drag the truck and trailer's tires cause to the load with the type of tire they use. Installing and using tires that have a low rolling resistance, along with with proper alignment, tread depth, and the right tire inflation, can increase the fuel efficiency of their semi truck.

Reduction in Engine Idling

Certain types of semi trucks can idle as much as seven hours a day, and reducing the amount that an engine idles while the truck is stopped, can help reduce fuel consumption. This could add up to a lifetime payback fuel savings of up to $74,000 for the truck.


The aerodynamics on a truck and trailer can add resistance to the transport and decrease gas mileage because of its large, bulky shape. So, by making semi trucks more wind-resistant, they can use less diesel for every mile they drive. Here are several aerodynamic improvements truck manufacturers are making and implementing in some types of semis.

  • Fairings

The space between the truck's cab and the front of its  connected trailer create several feet of space which act as a wind tunnel, creating drag on the entire semi and trailer. As the wind travels over and around the sides of the cab and down into this empty cavity, the wind pushes onto the front of the trailer. Many trucking companies and truck manufacturers are adding fairings onto the side of their trucks to block this space off, preventing wind from traveling between the truck and trailer.

  • Side Skirts

Another way to cut down on wind drag on a semi trailer is by adding side skirts on the sides of the trailer, between the front and back tires. These are great  for anyone searching for a used commercial truck for sale, as they can be installed on pretty much any semi. These panels extend downward to the pavement and cover the open space, preventing drag-causing wind and air from traveling under the trailer and increasing the truck's aerodynamics.

  • Round Caps on Rear Door

The flat rear doors of the trailer is also an area that can cause wind drag on a transport. A round or tapered cap installed over the back door would prevent wind from creating a suction, which pulls the trailer back while it is in motion. Tests are being conducted on this type of trailer alteration.

  • Covered Rear Wheels

Covering the rear wheels of a trailer with panels can help decrease the truck trailer's wind resistance. The panels prevent air from blowing between the wheels and axles, which normally causes drag on the transport. So, if you start seeing semi trucks with the trailer's wheels covered, it is not intended to improve the transport's visual appeal.

  • Wider Single Tires and Wheels

Recent tests using "super single" wide wheels to replace the dual wheels on a semi truck have been shown to improve fuel mileage by seven percent. This change alone is close to achieving the EPA's 10 percent increase in efficiency and will help reduce fuel costs for trucking companies each year.

With these improvements on semi trucks, fuel efficiency can be increased.