How One Fleet Discovered Holes in Its Fuel-Economy Strategy

What do you do when the aerodynamic devices you’ve chosen don’t work as well as expected in your fleet? If you’re Brad Pinchuk, president and CEO of Hirschbach Motor Lines, you find someone to help you with some testing.

“I think we got a little frustrated with trying to figure out what worked and what didn’t work and so forth,” Pinchuk says. So he turned to Mesilla Valley Transportation, which has long been known as a pioneer in testing fuel-saving solutions, whether its own inventions or commercial products. Now it’s offering testing services to other fleets.

Heading up Mesilla Valley Transportation Solutions is Daryl Bear, lead engineer and chief operating officer. “He’s been a nice addition to our fuel economy team, if you will,” Pinchuk says, “which saves us a lot of time as well as helping us make good decisions.”

Hirschbach, based in Dubuque, Iowa, runs 2,000 tractors and 3,500 trailers. The truckload company provides refrigerated services to all 48 states, with a special focus on high-density lanes throughout the eastern U.S., as well as dedicated, short, regional and long haul service with refrigerated, dry freight and specialized equipment.

Pinchuk sought out MVT Solutions to conduct fuel economy testing on a variety of tractor and trailer components, including various aerodynamic devices from different manufacturers. In particular, the carrier needed accurate data on the effect of different trailer skirts, under carriage devices, rear trailer devices, wheel covers and mud flaps.

Once it has fully implemented the resulting trailer aero recommendations, Hirschbach projects it will save $8.4 million.

“By using MVT Solutions for testing a combination of trailer aerodynamic technologies, we are realizing a 10.5% improvement in mpg compared to our baseline,” Pinchuk says. “Once the entire fleet is fitted with the solutions, we expect fuel savings of 2.8 million gallons annually.”

MVT Solutions, a New Mexico-based subsidiary of Mesilla Valley Transportation that was founded in 2016, provides fuel economy testing based on race car engineering. This high-tech testing methodology can obtain accuracy up to .25% and accounts for such variables as wind, driver behavior and duty cycle. 

Pinchuk says for his operations, that last one is really important. “It’s one thing getting test results that say you can improve fuel economy by 5%; it’s another thing understanding how that translates into your fleet based on things like the various mph your fleet is running.” Aerodynamic devices work best at highway speeds, so a fleet running a lot of operations at lower speeds may not see the same benefit as advertised. “Daryl does a really nice job of not only validating results at highway speeds but also based on your fleet, helping you understand what you can net out of it.”

Pinchuk also says MVT Solutions’ proprietary fuel economy testing methods are faster and less expensive than full-blown SAE/TMC economy-testing protocols —although he insisted on proof.

“I was still somewhat skeptical, so we took Daryl to a track and did the full-blown test on a track, and sure enough, it turned out they were virtually identical to his test. The fact that he’s not selling anything is also comforting. And he’s coming from a fleet that’s a best fuel economy fleet, which lends a whole lot of credibility to the entire process. We went in a different direction as a result of that testing.

“We have skirts on all of our trailers, and we know there’s an opportunity to have another maybe up to 4% at highway speed improvement, depending on how we attack the rear of the trailer,” Pinchuk explains. But until recently, the options available for the rear of the trailer were limited, and Pinchuk had reservations about maintenance costs and the fact that driver action was needed to deploy older products.

After testing, Hirschbach decided to install Michelin’s new Energy Guard wake reducer tab, which works like a spoiler and reduces the air recirculation zone behind a trailer at highway speeds.

Cutting idling costs

MVT Solutions also did testing on auxiliary power units, which are another area where Hirschbach is rethinking its strategy. It discovered diesel fuel consumption was higher than expected.

“We’re still searching for the right answer,” Pinchuk says. Hirschbach was an early adopter of electric APUs to provide heat and air conditioning for drivers without idling during their rest breaks. But there were problems with them not lasting all the way through the off-duty period, so the company went back to diesel APUs.

With more recent advances in battery-powered APUs, Hirschbach is testing the newer generation, as well as testing the impact of using only a bunk heater without an APU. “We’re trying to find the right balance between providing the driver the right comfort and the lowest cost solution for keeping the driver comfortable, and obviously that’s the cost of the investment in the device as well as the fuel that might burn and the maintenance costs,” Pinchuk says.

“A lot of that has to depend on your fleet as well; the answer for one fleet is not necessarily the same as for another fleet. One of the challenges for us is we have different fleets within the company as we’ve grown, and in a lot of shorter haul regional applications, what appears to be the right answer there, is different than what it would be in our longer haul fleet, for example. But does that make sense to take away the advantage of having a fungible fleet where you can switch trucks back and forth? Those are some of the challenges that we face.”

Part of the decision process is understanding how much the diesel APU is burning in fuel, he says, and that’s where MVT Solutions came in.

Conventional wisdom says that APUs burn significantly less fuel in heating mode than in air conditioning mode. But with MVT’s help, they discovered the fleet’s trucks were burning just as much in heating mode. The answer? Hotel loads.

“When the drivers are putting a load on the system, using TVs or microwaves, even though it’s providing heat from the bunk heater at low cost, the APU has to turn on to charge up the batteries, and it’s consuming a lot of fuel that’s not needed for heat. Daryl helped us understand you’re really consuming a lot more fuel than you think.”