application, vehicle type, the type of terrain the
vehicle drives on and more. In many cases, these
solutions are customizable to fi t the use of the
tractor and trailer.
“For example, we have one component that’s
fundamentally focused on dry vans,” says
SmartTruck’s Ingham. “It can’t be put on a refrigerated
trailer because of the refrigerated unit on
the front. With diff erent types of personalized
features on trailers, we are able to customize
aerodynamic solutions around that.”
Other factors to consider are whether the device
will work with the trailer specs, including length
and height, and with work performance devices
such as lift gates, ramp operations and diff erent
types of doors, adds Chris Lee, vice president of
engineering for Great Dane. Great Dane is a manufacturer
of truck dry van, refrigerated van and
fl atbed semi-trailers.
Here is a basic overview of each of the basic
trailer aerodynamic devices, and which area of
drag they help to reduce:
Side skirts—Help reduce aerodynamic drag
under the trailer where air hits the trailer’s rear
axles. Th ese devices help guide air around the
sides and to the back of the trailer.
Trailer tails—Help minimize the low-pressure
vacuum that occurs directly behind the trailer.
Th is is typically the area that creates the largest
amount of drag, so improving the aerodynamics
of this part of the trailer can help improve
vehicle stability and fuel effi ciency.
Nose fairings and gap reducers—Designed to fi ll
the area between the tractor and the front of a
dry trailer, helping to shield from crosswinds
and reduce drag on the front of the trailer.
Wheel covers and mudfl aps—Help reduce turbulence
and drag around the wheels, which helps
improve fuel effi ciency.
Oft en, diff erent types of aerodynamic devices will
complement each other. For instance, a fl eet may
choose to use a trailer tail and a side skirt to address
both undercarriage drag and drag at the rear of the
trailer. Employing one aerodynamic device does not
preclude a fl eet from installing another.
22 Fleet Maintenance | November/December 2018
Trailer aerodynamic
solutions are not
a one-size-fits-all
purchase.
Fleets have the option of installing aerodynamic
solutions piecemeal, or selecting an aerodynamic
trailer solution kit.
“Michelin off ers a kit for use on 53’ dry-van
truck load, refrigerated truck load and other
long haul and super regional applications,” notes
Calvin Bradley, aerodynamics technical lead for
Michelin North America. “Th is integrated kit eliminates
the need to combine elements from various
vendors. Solutions put together from diff erent
parts that someone combines may not necessarily
work together, and therefore, may not deliver
the expected results.”
While known for tires in nearly every tire
market, Michelin North America also manufactures
aerodynamic devices. Th e company recently
introduced an aerodynamic trailer kit at the
Technology & Maintenance Council’s Annual
Meeting earlier this year.
“Kits are only successful to the extent that it
makes sense for the fl eet to buy all of the components
of the kit together,” adds Josh Butler, president
of vehicle aerodynamics device provider
FlowBelow. “For example, if the kit is validated
to provide a certain fuel economy, and the components
of the kit are designed to work well together.”
When a kit is proven to work for the fl eet’s
application, it takes the guesswork out of deciding
which aerodynamic options from which manufacturers
are going to work well together to achieve
the desired effi ciencies. Th ese all-inclusive kits
can simplify the buying process.
On the other hand, aerodynamic kits do not
off er the same degree of customization that selecting
solutions individually might off er.
“When selecting aerodynamic devices for trailers,
fl eets should work closely with aero device suppliers
and trailer OEMs to get the most eff ective solutions
for their operations,” Lee suggests. “One-size-fi ts-all
approaches will not work as eff ectively.”
To ensure they select appropriate aerodynamic
devices for their equipment and operational
needs, fl eets should consider discussing their
options with the OEM and the device provider.
Th ey will be able to help determine whether a kit
or a more customized approach is appropriate for
the fl eet’s unique operation.
What to look for in an effective
aerodynamic solution
Improving fuel effi ciency and overall vehicle
effi ciency is a worthy goal, but fl eets also need
to consider whether a particular device will
» It is important to consider whether the
aerodynamic device is suitable for the application.
Photo courtesy of SmartTruck
» Aerodynamic devices can be a branding tool that helps promote the carrier’s image.
Photo courtesy of FlowBelow