When trying to cut down on fleet spending, maximizing fuel efficiency and minimizing engine idling can make a big difference in fuel costs and component wear and tear on a vehicle.
“At current prices of $4 per gallon, a 10-hour rest period comes out to $32,” noted Sean O’Connor, division manager for Go Power Fleet in 2023. “However, the cost of idling is more than just the cost of fuel. One hour of idling is estimated to cause roughly 175 miles of engine wear. The related maintenance costs quickly jump into the tens of thousands of dollars.”
This is often where auxiliary power units (APUs) come in. These devices can power the truck without the engine via stored battery power or from the vehicle's diesel tank. As a result, they can offer emissions-reduction benefits along with greater fuel efficiency, all while keeping reefers cold and drivers comfortable in the cab.
Here are a few APU options on the market today to help lower truck equipment costs, as well as a some insights from fleets who've used these brands.
Dragonfly Energy Battle Born All-Electric APU
Dragonfly Energy’s Battle Born All-Electric APU provides power for HVAC, appliances, and amenities in the cab without the need for idling, while also reducing fuel and maintenance costs. The lithium-ion unit has a pre-wired box for easy installation and the low-profile design allows it to fit between the frame rails. Wireless monitoring is available to track true state of charge and battery health. ROI can be expected in under two years, the company said.
“We can finally get through the 10-hour rest periods,” said Mike Monolo, director of maintenance at USXL. “This has increased mpg which also allows one less oil change per year and now zero DPF in our 2-3 year ownership.”
Thermo King 3rd Generation TriPac APU
The 3rd Generation TriPac APU from Thermo King offers additional features to reduce emissions and monitor performance. Available in two models, the standard and the aftertreatment device model, the TriPac APU eliminates unnecessary engine idling and provides telematics capabilities. The standard model is a 49-state EPA Tier 4 compliant solution, THermo King stated, while the aftertreatment device model is 50-state compliant for both CARB and EPA Tier 4 regulations for new OEM or aftermarket installs. Thermo King’s TracKing telematics is available for both models, which both include an updated controller and in-cab digital user interface.
“The cold weather we operate in sometimes requires trucks to be left running or travelling back to a location to plug in or be put inside. Now with the Thermo King APU, we can leave the units at the location where we will be starting our shift, or loading and unloading,” said Sheldon Duffy, branch manager at NCSG Crane & Heavy Haul. “We are seeing fuel savings, considerably less idling on our engines, and most importantly, increased driver comfort.”
DClimate Hybrid APU
DClimate’s Hybrid APU combines a high-efficiency 48V HVAC module with a battery management and rapid recharge system to deliver a low overall emissions profile, the company said. The Smartway-verified DClimate system offers full 50-state emissions compliance, functions even under severe conditions, and delivers lower operational costs and total cost of ownership. The system design enables continuous and uninterrupted availability without compromising battery life and is backed by a four-year warranty.
“The DClimate System has helped in lowering our auxiliary equipment cost and is an important tool in management of truck idling,” said Johnny Branstine, VP of maintenance for National Carriers. “Over the past six years, as a fleet we have transitioned from diesel APUs to 100% DClimate. Reliability is key and coupled with the durability that we see in this product, we feel the product will even serve second owners well.”
