Stainless steel tanker trailers look smooth enough to easily slip through the air, but they have characteristics that cause drag: an inevitable gap behind the tractor and ahead of the tank's nose, where turbulence forms, plus fenders, walkways and ladders that grab at the air.

Indian River Transport, a large Florida-based transporter of food-grade commodities whose rigs run in 48 states as well as Canada and Mexico, has about 800 of these tankers, mostly Walkers, along with 650 tractors. Like all economy-minded managers, the fleet’s executives look for ways to save fuel, and found one with a new product from FlowBelow Aero.

The device includes quick-release wheel covers and a pair of fairings installed between and behind the wheels of a tractor’s tandem. They control the complex airflow around the otherwise exposed wheels, and beneath the trailer's forward fenders. FlowBelow said its testing showed the patented AeroKit system reduces aerodynamic drag and improves fuel efficiency of a rig by 2.23%.

Indian River’s own in-service tests on four tractors showed even better results: more than 3% higher fuel economy versus tractors without the kits, said Mark Gressett, the fleet's safety director.

“We tested the AeroKit in our fleet for over seven months, starting in January specifically to test the product’s winter durability and performance,” he said, noting that there are limited options for improving the aerodynamic performance of a tanker trailer. “We were impressed with the product’s durability, ease of use, fuel efficiency performance of over 3% and investment payback in less than one year.” 

Indian River has begun installing the kits on other tractors, and if they continue to prove out, they'll probably be completely phased in, Gressett said. An AeroKit retails for $1,800, but with volume pricing the fleet is paying less than that.  

Controlling air flow should also reduce water spray and improve visibility, but for Indian River “the main thing is the fuel economy,” he said. “We found it worthwhile. It exceeded our expectations.”

FlowBelow, in Austin, Texas, was founded by mechanical and aerospace engineers, Josh Butler and Kyle Walker, the company said. Their product development process includes advanced computational fluid dynamics modeling and extensive interaction with fleet mechanics and drivers to ensure the products provide utility, efficiency, and profitability.