Tractor Gap Devices

The gap between the tractor and trailer has long been a point of known challenges for optimizing aerodynamics.  New solutions are now appearing in the marketplace that are significantly different from past ideas.

Introduction & Rationale

Tractor-to-trailer gap closure efforts started with cab extenders, sleeper extenders and most recently added sleeper top extenders to the cab.  Devices for the front of the trailer have been around for years.  Recently new devises have entered the market to deploy at speed to close the gap and then retract as vehicle speed decreases.

Available Systems

Two new systems are in early stages of adoption.  One unfolds to close the gap to the trailer in an origami style mechanism while the other inflates to create a gap closing curtain.


Early feedback shows that savings could be as high as 4 to 5% depending on your equipment, weather conditions, time spent deployed and other factors.

Less fuel burned means less engine emissions and less engine wear.

With many fleets having 3 or more trailers for every tractor, implementing solutions on the tractor are more advantageous and affordable than adding devices to the trailers.

Handling and steering become easier if there is no wind buffeting of the trailer.

Use of these systems may allow fleet to run shorter extenders and avoid the cost of damaged extenders.


These systems add at least a minor amount of weight to the vehicle

The system adds electronic controls in addition to the physical components

It isn’t hard to find a tractor with damaged cab extenders so protecting these devices from damage is a challenge unless designed to stay out of the trailer swing path.



AeroWall Dynamics