Roof fairings will improve fuel efficiency, and the more aerodynamically shaped the roof air fairing, the better the fuel economy.
For 53′ dry vans and refrigerated trailers, full height roof fairings create a smooth transition from the windshield to the full height of the trailer. These fairings may simply be the top of a full-height sleeper cab or an additional part above a low, mid, or high cab.
For day cabs, a roof fairing is often an additional part that can be mounted to the low-roof cab. In some cases, an adjustable roof fairing can be installed and lowered to limit drag when the tractor is not pulling a trailer.
For tanker or flat bed trailers, tractors and their cab height should be specified to match the trailer as best as possible. Using a full-height cab that generally matches a 53’ van trailer will create higher drag than needed and thereby increase fuel expense up to 10%.
Due to lower drag.
Sharper, Integrated Appearance
A roof fairing and cab designed as one integrated system improves vehicle appearance.
Historically, add-on aerodynamic features for tractors incurred a higher initial cost. This is still the case for some of the optional devices.
Not Suited to All Applications
Full-height roof air fairing decreases fuel economy in bobtail, or in trucks hauling flat or tanker trailers.