Heavy Duty Trucking Logo
MenuMENU
SearchSEARCH

Electric Axle for Trucks Saves Up to 15% in Fuel, Hyliion Says

The Hyliion 6X4HE system, which includes an electric APU that saves another 12% in fuel, is being tested by three major fleets.

Tom Berg
Tom BergFormer Senior Contributing Editor
Read Tom's Posts
October 18, 2017
Electric Axle for Trucks Saves Up to 15% in Fuel, Hyliion Says

Green-painted Hyliion 6X4HE components include the motorized rear axle, lithium-ion battery pack, electronic controls, and electric APU.   

3 min to read


Mesilla Valley, PAM and Ryder are each testing a Hyliion electric-powered axle. The device supplies supplemental power and saves up to 15% in fuel, its maker says. Photos: Hyliion Inc.

An electric-powered axle for highway truck-tractors has been announced by Hyliion Inc., a startup technology company that has been developing a similar product for semitrailers. The truck version is now being tested by three major fleets, the company said.

Hyliion’s 6X4HE system generates electric power on downgrades or while coasting, and supplies supplemental power during launch and on upgrades, explained Thomas Healy, founder and CEO. He said the system delivers substantial fuel savings, lowers exhaust emissions, and eases work for the driver. 

Ad Loading...

A Hyliion axle replaces a 6x2 truck’s non-driven dead axle or is added to a 4x2 truck, turning either into a 6x4. Existing 6x4 tractors can be converted by removing one mechanically driven axle and replacing it with a Hyliion axle.

The system includes a motorized axle, lithium-ion battery pack, and electronic controls. The battery pack also runs an auxiliary power unit during rest periods. It can be installed on a new or existing truck in about three hours.

Mesilla Valley Transportation, PAM Transport, and Ryder System all participated in testing and refining the 6X4HE, and each has one tractor running with it, Healy said.

Ad Loading...

Hyliion (pronounced HIGH-lee-on) first announced a powered trailer axle last year, but switched its focus to a truck system at the request of fleet executives. The axle’s hybrid action alone will save 15% in fuel, the company claimed.

“Fleets said they’d see a faster payback if it could be put on a truck because it would be used more often than on a trailer,” Healy told HDT. “We listened and focused our efforts to first deliver the 6X4HE System with an innovative APU” that uses the battery pack.  

The APU includes an air conditioning compressor and blower to deliver 18,000 Btu’s for up to 10 hours to cool a sleeper in warm weather. This saves an additional 12% in fuel. Fleets are using a diesel fuel-fired heater to warm the sleeper, Healy said. In addition, two outlets provide electricity in the cab and sleeper.  The system can also be plugged in to shore power. 

Green-painted Hyliion 6X4HE components include the motorized rear axle, lithium-ion battery pack, electronic controls, and electric APU.

The 6X4HE easily attaches to the truck frame and is self-contained, he said. PAM used a new Peterbilt 4x2 tractor, while MVT and Ryder converted in-service International and Freightliner 6x2 tractors, respectively. Systems operate autonomously with no driver involvement.

“Electrification is the talk of the industry,” said Scott Perry, chief technology and procurement officer for Ryder Fleet Management Solutions, in the Hyliion announcement. “Hyliion provides a creative solution for long-hau,l over-the-road trucking that we feel will be of interest to current diesel fleets that are looking for an advanced technology that they can pursue in the very near future.”

Ad Loading...

“We are excited to be a part of the testing process with Hyliion on a product that has the potential to be industry-changing,” said Paul Pettit, vice president, maintenance, at PAM Transport. “The Hyliion team is great to work with.”  

“Innovation in fuel savings is nothing new to Mesilla Valley, but Hyliion’s system is the only thing we’ve seen that can make such a big impact,” said Royal Jones, MVT’s CEO.

Hyliion is currently taking orders for the 6X4HE with production starting next month. Pittsburgh-based Hyliion, founded in 2015, recently announced investment of $21 million from venture capitalists, and this will help fund the production, Healy said. More information is at http://www.hyliion.com.

More Fuel Smarts

Collage of HDT Top Green Fleets with logo
Fuel Smartsby Deborah LockridgeMay 18, 2026

Top Green Fleets 2026: How Fleets Are Reducing Emissions in the Real World

What works in sustainable trucking today? Heavy Duty Trucking's Top Green Fleets are finding practical ways to cut fuel use, reduce emissions, and keep freight moving.

Read More →
Tesla Semi electric truck on display at ACT Expo
Fuel Smartsby News/Media ReleaseMay 13, 2026

California Launching $1 Billion Electric Truck Rebate Program

CARB says the California Clean Fuel Reward program will begin offering point-of-sale rebates of up to $120,000 for electric commercial trucks starting June 26.

Read More →
Closeup of engine in Mack truck
Equipmentby Deborah LockridgeMay 13, 2026

Mack Unveils EPA 2027-Compliant MP13 Engine With More Power, Better Fuel Economy

Along with unveiling its EPA 2027-compliant MP13 engine, Mack outlined powertrain changes across its Class 6-8 lineup, including new Cummins-based X10 engines.

Read More →
Ad Loading...
Crowd at Volvo booth at ACT Expo
Equipmentby Deborah LockridgeMay 8, 2026

How Volvo’s New D13 Engine Meets EPA 2027 Emissions Without Sacrificing Power or Fuel Efficiency

Volvo says advances in combustion and aftertreatment helped its new EPA 2027 D13 engine avoid the fuel-economy penalties many once expected from tighter NOx emissions limits.

Read More →
Two men in chairs on stage with big video screen behind them showing Tesla Semi
Fuel Smartsby Deborah LockridgeMay 7, 2026

'TCO’s Here.' Tesla Says Electric Semi Economics Are Ready for the Mainstream

Tesla’s Semi chief at ACT Expo outlined production growth, lower-cost models, charging expansion, and why the company believes fleets are leaving money on the table by waiting on electric trucks.

Read More →
Electric semi trucks parked at a charging station with overhead charging equipment, representing challenges in heavy-duty EV infrastructure deployment.
Fuel Smartsby News/Media ReleaseMay 5, 2026

What Will It Take to Scale Electric Truck Charging? New Electrification Coalition Report Identifies 11 Solutions

A new report from the Electrification Coalition outlines key barriers slowing electric truck charging deployment and offers policy solutions to accelerate infrastructure growth.

Read More →
Ad Loading...
NACFE Run on Less 2026 findings.
Fuel Smartsby Jack RobertsMay 1, 2026

NACFE: Fleets Need to Recalibrate TCO Strategies as Electric Trucks Gain a Long-Term Edge

NACFE’s Run on Less data has found that recent setbacks aside, electric truck powertrains are trending toward market leadership by 2025.

Read More →
Gray Volvo tractor pulling trailer on open highway
Fuel Smartsby Deborah LockridgeMay 1, 2026

New High-Horsepower Natural Gas Engine Could Expand Fleet Options

Westport and Volvo are demonstrating a 500-hp truck with diesel-like efficiency — one that also offers what Westport says is a better pathway to using hydrogen fuel in trucks.

Read More →
Illustration with oil wells silhouetted against red and gold sky
Fuel Smartsby Deborah LockridgeMay 1, 2026

Why Fuel Diversification Matters for Trucking Fleets

Relying on diesel alone exposes fleets to fuel price volatility. Here’s why diversification with electric, natural gas, and renewable fuels can reduce risk.

Read More →
Ad Loading...
Range Energy eTrailer.
Fuel Smartsby News/Media ReleaseApril 17, 2026

Range Energy Confirms eTrailer Performance in Winter Testing as Commercial Rollout Nears

Range Energy said its production-ready eTrailer system proved it can boost stability, safety, and efficiency in sub-zero winter conditions as the company moves toward scaled deployment.

Read More →