Fuel-saving specs and strategies that work for one company won’t necessarily work for another, even if they’re in similar applications. As we spoke with current and former HDT Truck Fleet Innovators for our June cover story on ways to save fuel, it became evident that idle reduction and the use of auxiliary power units are a perfect example of how fuel-saving specs are not one-size-fits all.

Hirschbach Motor Lines, Dubuque, Iowa, tried to reduce weight and cost by not installing APUS on its tractors, opting for a start/stop idle management system on the engine, says Nick Forte, director of equipment assets and facilities. (CEO Brad Pinchuk is a 2021 Innovator.) “This did not provide the results as anticipated, and the driver feedback was less than acceptable,” he says, so they went back to diesel APUs.

U.S. Xpress, Chattanooga, Tennessee, has been proactive in adopting electric APUs, working with D-Climate, says Shaun Sadler, senior vice president of equipment at U.S. Xpress and a 2021 Innovator. “Idle optimization has contributed significantly to reduced fuel usage and has aided in really managing driver idle. We believe there will be additional gains in battery health and reduced service requirements.”

Navajo Express had a different experience with APUs.

“We had originally installed APUs on our tractors for both fuel economy and driver comfort benefits,” says Don Digby Jr., president of Denver-based Navajo Express and a 2019 Innovator. “We found that the weight of the APUs, along with maintenance needs, were in fact hurting Navajo’s fuel economy. We have since began to trade out trucks with APU units.”

Idle Reduction Beyond the APU

One thing that likely would have broader application? Driver education and incentives.

At Maverick Transportation, for instance, a key part of its Pay For Perfomance incentive program is idle percentage, says Mike Jeffress, vice president of maintenance at the Arkansas-based flatbed fleet and a 2012 Innovator. As part of the PFP program, he says, “Drivers receive updates daily and fully understand their performance based on the quarterly goal as well as how they rank within the fleet assigned.”

Gerry Mead, executive vice president of maintenance and equipment for Hub Group and a 2016 Innovator, believes one thing many fleets overlook in fuel economy is driver training, whether it’s the right way to work with a new transmission or staying comfortable in the bunk. “How do you idle the right way? You have to pre-cool the bunk area and really control your idle time,” he notes.

Even though idle management can be a significant contributor to reduced fuel utilization, Sadler says, “Idle management is not always the most popular subject nor the easiest to manage. As technology expands, we are utilizing better tools to help in this regard. As well, we have found that good solid communicating with drivers can assist considerably.”