Fuel efficiency has become an increasingly important concern for trucking companies as elevated diesel prices squeeze operating budgets. Now, a redesigned trailer device promises to reduce fuel consumption without requiring fleets to replace trucks or make major mechanical changes.
Texas-based FlowBelow Aero has introduced its updated Trailer AeroSlider system, claiming potential savings of three U.S. gallons of diesel for every 1,000 miles travelled. The technology reduces aerodynamic drag around a trailer’s wheels and suspension, targeting an often-overlooked source of fuel consumption.
With U.S. diesel prices recently reaching record levels, even relatively small improvements could translate into meaningful savings. Independent testing supports the technology’s potential, although actual results will depend on trailer configurations, operating conditions and annual mileage.
A New Product Arrives at a Costly Moment
FlowBelow unveiled the redesigned Trailer AeroSlider on October 18, 2026, during the American Trucking Associations’ Management Conference & Exhibition in Charlotte, North Carolina. The system is designed for commercial trailers, particularly the dry vans and refrigerated trailers commonly used to transport consumer goods, groceries and other freight across North America. Rather than modifying the engine or drivetrain, the technology focuses on reducing the resistance a truck encounters while travelling at highway speeds.
The timing is significant. According to the U.S. Energy Information Administration, the national average on-highway diesel price reached US$6.529 per gallon on September 21 before easing to US$6.179 on October 12. Although prices retreated from their peak, fuel remained a considerable operating expense for transportation companies. Higher diesel costs can affect everything from freight rates to delivery budgets. For fleets operating hundreds of thousands of miles annually, equipment that reduces fuel consumption without interrupting regular operations can become increasingly attractive.
Why Aerodynamics Matter Beneath the Trailer
When a tractor-trailer travels down a highway, its engine must overcome more than the weight of its cargo. Air resistance becomes a major factor, particularly at higher speeds. While modern trucks have streamlined cabs, exposed trailer wheels, suspension components and underbody structures can still disrupt airflow. This turbulence creates drag, meaning the engine must use additional energy to maintain speed. Much of that resistance is difficult to notice from the driver’s seat, even though its effects accumulate over long distances.
The importance of trailer aerodynamics has been demonstrated through government research. A Transport Canada study conducted with the National Research Council examined several drag-reduction technologies using sophisticated wind-tunnel testing. Researchers found that properly designed trailer side skirts and other aerodynamic improvements could meaningfully reduce fuel consumption. Their work also showed that different trailer configurations respond differently to aerodynamic changes. That distinction matters because a device delivering measurable improvements under controlled conditions may produce different results when fitted to equipment operating on busy highways.
Three Components Work Together to Reduce Resistance
The new AeroSlider combines aerodynamic trailer wheel covers, flow-through mud flaps and redesigned rear fairings. Each component addresses a different part of the airflow problem. Wheel covers help smooth the surface of exposed wheels, while specialized mud flaps are intended to reduce resistance compared with conventional designs. The rear fairings direct air slightly outward and backward as it passes the trailer’s tandem wheels, reducing turbulence around the suspension and surrounding underbody.
One practical feature is the system’s placement on the trailer’s sliding tandem suspension. Trucking operators frequently adjust tandem axle positions to distribute cargo weight appropriately. Because the AeroSlider moves with the suspension, its components remain positioned around the wheels as those adjustments occur. This approach is intended to preserve aerodynamic performance without requiring drivers to reposition the equipment separately. FlowBelow also emphasizes that the system works alongside existing trailer side skirts, allowing fleets to improve aerodynamic efficiency without necessarily removing equipment they have already purchased and installed.
What Independent Testing Found About Fuel Savings
The central claim behind the redesigned AeroSlider comes from fuel-economy testing conducted by MVT Solutions, an independent testing organization. In June 2026, the company evaluated the updated rear fairings and flow-through mud flaps using 2019 International LT tractors pulling loaded 53-foot dry van trailers. Importantly, the trailers already had aerodynamic side skirts and wheel covers. Adding the redesigned components produced measured fuel savings of 1.77 gallons per 1,000 miles compared with that baseline configuration.
The remaining savings come from separate testing of FlowBelow’s trailer wheel covers. MVT Solutions previously measured a reduction of 1.23 gallons per 1,000 miles using a 48-foot refrigerated trailer equipped with side skirts. Combining the two results produces FlowBelow’s advertised three-gallon figure. However, the distinction is important: the headline number combines results from different tests rather than representing one direct measurement of the entire redesigned package under identical conditions. The individual results provide evidence of potential efficiency improvements, but actual fleet savings should not be treated as guaranteed.
Why the Advertised 2.5% Improvement Needs Context
FlowBelow estimates that the complete AeroSlider package can improve fuel efficiency by approximately 2.5%. While that percentage may appear relatively small, trucking companies often operate on narrow profit margins where modest efficiency improvements matter. The percentage also depends on the truck’s existing fuel consumption. For example, a vehicle averaging seven miles per gallon uses approximately 143 gallons over 1,000 miles. Saving three gallons in that situation would represent a reduction of roughly 2.1%, rather than exactly 2.5%.
Existing aerodynamic equipment is another important consideration. A trailer that already has FlowBelow wheel covers cannot reasonably count their previously achieved savings as an entirely new benefit. For that configuration, the 1.77-gallon fairing and mud-flap result provides a more useful reference point. The U.S. Environmental Protection Agency also cautions that different aerodynamic devices do not always produce predictable results when combined. Consequently, fleets should evaluate the additional improvement delivered by the new components rather than assuming every advertised efficiency gain can simply be added together.
How Much Money Could Trucking Fleets Actually Save?
The financial appeal becomes clearer when the claimed fuel savings are applied to annual trailer mileage. A trailer travelling 30,000 miles per year could potentially save 90 gallons of diesel. At the U.S. national average price of US$6.179 per gallon recorded on October 12, that would represent approximately US$556 in annual fuel savings. For a trailer covering 50,000 miles, the potential improvement rises to 150 gallons, worth approximately US$927 at the same price.
Over five years, those reductions could become substantial. Using a slightly lower diesel assumption of US$6 per gallon, FlowBelow estimates five-year fuel savings of US$2,700 to US$4,500 for trailers travelling between 30,000 and 50,000 miles annually. The company has suggested potential payback periods of roughly eight to 13 months, depending on usage and operating costs. Those projections remain conditional, however. Actual returns depend on equipment purchase and installation expenses, diesel prices, annual mileage and whether real-world fuel savings match the testing results.
Lightweight Installation Could Make Fleet Adoption Easier
One of the redesigned AeroSlider’s selling points is its relatively straightforward installation. According to FlowBelow, the complete system weighs less than 30 pounds and can be retrofitted to an existing trailer in under 45 minutes. It is intended to accommodate most dry van and refrigerated trailer configurations, making it potentially useful for fleets that want to improve efficiency without replacing otherwise serviceable equipment. Once installed, the aerodynamic components function without requiring drivers to activate or adjust them during normal trips.
That simplicity could be particularly valuable for transportation companies managing large numbers of trailers. Taking equipment out of service for lengthy upgrades creates scheduling challenges, especially when delivery commitments are already tight. However, installation time represents only part of the ownership experience. Maintenance departments would still need to assess component durability, clearance, accessibility and compatibility with existing equipment. Damage from road debris, routine repairs or trailer modifications could also affect long-term costs. The short installation estimate is encouraging, but fleet operators should confirm actual fitting requirements before committing to a widespread rollout.
The Redesign Addresses Problems With an Earlier Version
Although it has a new look, the AeroSlider is not an entirely new concept. FlowBelow publicly introduced an earlier version in October 2017, pairing aerodynamic wheel covers and mud flaps with fairings around the trailer’s tandem wheels. That original design did not remain on the market. In an October 2026 interview with Truck News, company founder Josh Butler explained that the centre fairing created mounting and durability challenges, prompting FlowBelow to withdraw the product. The history highlights an important reality in commercial trucking: equipment must withstand demanding conditions while delivering measurable efficiency improvements.
The redesigned AeroSlider eliminates the troublesome centre fairing, replacing the earlier arrangement with an optimized rear fairing that FlowBelow says provides better aerodynamic performance. Engineers used computer airflow modelling, wind-tunnel research and track testing during development. Removing unnecessary components should simplify installation and reduce potential maintenance concerns. However, the redesigned system’s long-term durability still needs to be demonstrated through everyday fleet operation. Mechanics will want to examine mounting hardware, component accessibility and resistance to routine road damage before widespread adoption.
What the Technology Could Mean for Canadian Trucking Fleets
For Canadian trucking companies, the potential fuel savings are easier to understand when expressed in metric units. Three U.S. gallons equal approximately 11.4 litres, while 1,000 miles represent about 1,609 kilometres. That translates into a potential reduction of roughly 0.71 litres per 100 kilometres travelled. A trailer covering 50,000 miles annually could therefore save approximately 568 litres of diesel if the advertised performance is achieved. Canadian fleets must also account for differences in fuel prices, currencies and operating conditions when estimating financial returns.
Lower fuel consumption could provide environmental benefits alongside reduced operating expenses. According to the U.S. Environmental Protection Agency, burning one gallon of diesel produces approximately 10.18 kilograms of carbon dioxide. Saving three gallons would therefore prevent roughly 30.5 kilograms of direct tailpipe CO2 emissions per 1,000 miles. Over 50,000 miles, that could amount to approximately 1.53 metric tonnes of avoided CO2 emissions. These estimates assume the projected savings are achieved and exclude emissions associated with fuel production and equipment manufacturing. Nevertheless, improved aerodynamics offers carriers another potential way to reduce fuel consumption and emissions simultaneously.
Real-World Results Will Determine Whether Fleets Adopt It
FlowBelow says the redesigned Trailer AeroSlider is available directly for retrofit installations and can also be specified on new trailers through participating manufacturers. Its potential appeal extends beyond large transportation companies to smaller operators looking for practical fuel-saving upgrades. The U.S. Environmental Protection Agency’s SmartWay program has already established the value of trailer aerodynamic improvements and low-rolling-resistance tires in reducing fuel consumption. The AeroSlider represents another approach to improving the efficiency of equipment that remains heavily dependent on diesel.
The next challenge will be demonstrating consistent financial returns outside controlled testing conditions. Fleet managers considering the system should compare fuel consumption across similar routes, monitor maintenance requirements and calculate savings using actual trailer mileage. Purchase costs, installation expenses and equipment compatibility will also influence the investment decision. The available test results provide evidence that FlowBelow’s components can reduce fuel consumption, but the three-gallon headline remains a combined estimate rather than a guaranteed outcome for every trailer. With diesel expenses placing continued pressure on transportation businesses, the redesigned AeroSlider could become an attractive upgrade if its promised savings translate into reliable everyday performance.
