This past February, Mesilla Valley Transportation Solutions (MVTS)—a provider of fuel economy testing and design and development services for the trucking industry—ran a series of A/B tests on an AeroVolution Booster-Tail, an aerodynamic fuel-saving technology designed for Class 8 tractor-trailers. After analyzing the data, MVTS recently announced the results of the test: the device demonstrated a fuel savings of 5.04 gallons per 1,000 miles, or an improvement of 0.36 mpg.
The Booster-Tail is installed at the rear of the trailer. As the vehicle travels down the road, there is a natural vacuum against the rear of the trailer—suction that is pulling back on the trailer, explained Daryl Bear, lead engineer and chief operating officer of MVTS. “What the Booster-Tail does is reduces the ability for that suction to occur—that’s how it incurs fuel savings.”
Bear explained that as the air flows down the side of the trailer, upon reaching the back, that pressure is transferred to deploying the Booster-Tail rather than creating the dragging vacuum. The self-deploying mechanism will activate upon reaching highway speeds and divert air pressure. When the vehicle slows, or while parked, the Booster-Tail retracts and rests against the trailer doors.
The test
For the test, MVTS used two vehicles: 2018 and 2021 International LT 625s with Cummins 15L X15 engines. The equipped trailers both were 53’ Hyundai dry vans. In all, GVW was about 72,000 lbs.
The vehicles ran simultaneously around a 9-mile circle track, traveling at 65 mph. One vehicle was spec’d with the AeroVolution Booster-Tail, and the "compare" truck was not.
“It’s somewhat similar to an SAE J1321 test,” Bear said. “But with MVTS testing, we use flow meters and data acquisition… It’s a lot more high-tech.”
MVTS gathered data on fuel consumption, aerodynamics, rolling resistance, driver behavior, and other variables, and analyzed the data with proprietary methods.
The testing company also advocates for using the gal/1000 miles metric because measuring in mpg or percentage makes the results "prone to error from changing variables such as vehicle baseline fuel economy, load, driver behavior, and duty cycle."
The results
According to the data gathered and analyzed through MVTS’ testing, the AeroVolution Booster-Tail demonstrated a fuel savings of 5.04 gallons per 1,000 miles (4.18%).
“If a truck travels 100,000 miles a year, it’s 100 times that number of 5.04, so, you’re saving 500 gallons of fuel in a year. If you’re paying five bucks a gallon," Bear explained, "that’s $2,500 a year. It’s a pretty significant financial savings.”
This was just what the manufacturer of Booster-Tail was looking for.
“We wanted to get fuel economy data for the unique geometry of our device,” Lee Telnack, president of AeroVolution, told MVTS. “I was happy with the test results because they confirmed what we knew, and they echoed results we got from CFD studies.”
The implications
“Whenever you can reduce fuel consumption, there are a lot of other benefits that you get,” Bear said. “You’re not putting as much wear on the engine or the drive train because you’re not working it as hard. So, you’re saving fuel, and you’re improving maintenance, oil change intervals, that kind of thing. And by reducing the suction at the back of the trailer, it also improves the stability. You don’t feel it moving around as much.”
Furthermore, Bear acknowledged that fleets could positively impact their sustainability objectives through spec’ing such a fuel-saving technology via its reduction of greenhouse gas emissions and carbon usage.
“No one loses when you’re improving fuel economy,” he emphasized.
Bear did mentioned that previous iterations of boat tail systems “left a bad taste in a lot of people’s mouths.”
“But this system is worth looking at,” he stated. “It overcomes a lot of the issues from the previous trailer tail designs. It’s worth it for fleets to re-look at tail devices when it comes to the AeroVolution Booster-Tail.”
For the test, MVTS installed the Booster-Tail themselves. Bear said that compared to previous trailer tail systems they have tested in the past, “the installation of the Booster-Tail is much easier” as there were not nearly as many bolts or moving parts.
And when asked on what it would take to maintain the system long-term, Bear said that “it seems to be a pretty low-maintenance system.”
“It doesn’t have nearly as many metal parts, or fasteners, or hinges as the previous designs of this kind of system did,” Bear said. “We don’t think there will be as many things broken, or maintenance required, because the Booster-Tail closes on its own as the vehicle slows down. So, we don’t anticipate that there will be as many issues of backing into things, like what happened with previous tails… Other tails had a lot of metal, where if you backed into something it was a hard hit. The Booster-Tail is [made up of] composite panels—they’re a lot more flexible.”
