Executive Summary

Removing the fender or hood-mounted mirrors, grille guards, bug deflectors, sunshades, quarter fenders, and other features in the main air flow can lower resistance while the truck is in motion. Each individual part can have a minor effect on drag and fuel economy; combined, they can add up to reduced fuel efficiency by as much as a few percent.  Each 1% in fuel efficiency can be up to $700 in annual fuel savings, decreasing the value of these add-on parts and making them good candidates for removal.

For more information on the effectiveness of removing parts, we recommend contacting your tractor builder.

Tractor Aerodynamics
What Fleets Are Saying

“We continue to update our fleet with more fuel efficient post-2014 U.S. Environmental Protection Agency emission compliant engines, install aerodynamic devices on our tractors, and equip our trailers with trailer blades, which all lead to meaningful improvement in fuel efficiency.” — Knight Transportation

“Appearance and detail of our equipment means a lot to our drivers. Drive wheel fairings don’t just save us money, but our drivers like them too.” — Brad Pinchuk, Hirschbach

“Sleeper tractor aerodynamics have been finely tuned by all OEMs. Eliminating various features can add 10% to a fleet’s fuel expense,” — Chief engineer at a major truck builder.

 

Decision Making Tools

The Confidence Matrix has been issued to help fleets make decisions about tractor aerodynamic devices.

Decision-Making Tools

Conclusions
  • Fleets should use the standard, optimized aerodynamic packages developed by tractor manufacturers. 
  • Fuel efficiency can be lowered by about 10% by moving to partial or no aerodynamics.
  • Tractor and trailer ride heights should be matched for as many miles driven as possible.
  • Fleets operating day-cab tractors should pursue greater adoption of tractor aerodynamics.
  • Tractor manufacturers should design and make available aerodynamic features for day-cab tractors including those powered by natural gas.
  • Future EPA and NHTSA Greenhouse Gas Regulations will continue to challenge tractor builders to improve the aerodynamic drag of these vehicles.