Building an all-new, hydrogen fuel cell electric vehicle is itself a daunting task. Engineering one that is off-road capable presented a new level of challenges for the Colorado ZH2 team.
“The ZH2 integrates the strong foundation of the Colorado midsize pickup architecture with GM’s advanced hydrogen fuel cell propulsion technology,” said Jim Campbell, vice president, Chevrolet Performance Vehicles and Motorsports. “It combines the lessons Chevrolet has learned during 3.1 million real-world miles of testing hydrogen fuel cell-powered vehicles. It also reflects our commitment to expanding Chevrolet’s performance envelope off-road.”
The Colorado ZH2 is a demonstration vehicle that will be tested by the U.S. Army in 2017 to evaluate the effectiveness of a hydrogen fuel cell-powered off-road vehicle in mission settings.
The ZH2, powered by GM’s Hydrotec fuel cell technology, was unveiled Oct. 3 at the fall meeting of the Association of the United States Army (AUSA) in Washington, D.C. It makes its auto industry debut today at the 2016 SEMA Show.
Designed and engineered for zero compromises off-road
The ZH2 shares several components with the production Colorado, including the cab, doors and roof. The standard Colorado production cab was moved back 125mm to accommodate 37-inch off-road tires.
At the front, the ZH2 hood incorporates a power dome to accommodate a transversely mounted fuel cell stack. The front fascia is a dramatic departure from the production truck. Cooling was enhanced and moved to the rear to help regulate temperatures while exporting electric power in a stationary, hot environment.
The bold appearance of the Colorado ZH2 was driven by the packaging requirements for the fuel cell system, stationary power generation and chassis hardware necessary for off-road performance.
At the rear, the ZH2 features a clamshell cover that integrates air intakes feeding radiators honeycombed behind the rear doors. Moving the air intake near the roofline lessens the amount of dust and dirt ingested into the radiator during extreme conditions.
The clamshell also houses the Exportable Power Take-off (EPTO) electric power conditioning unit. This allows the operator to draw high-voltage D/C from the fuel cell and convert it to both high- and low-voltage A/C (240V or 120V). The EPTO unit delivers 25 kW continuously or up to 50 kW peak. The system can power a subdivision, tools at a worksite, communications equipment or a small field hospital for hours.
The hood, front fenders, rear fenders and bed hatch are fabricated from carbon fiber with Kevlar reinforcements for maximum strength and impact resistance. The ZH2 also features a custom 30-inch LED light bar, custom turn signals, and 7-inch front headlights.
Proprietary chassis designed, engineered and tested by Chevrolet
The chassis was designed and engineered for off-road use. It starts with 37-inch BF Goodrich tires mounted to 17-inch beadlock wheels. Power is transferred from the 93 kW fuel cell system to the 132-kW electric motor, which produces 236 lb.-ft. of instantaneous torque. That torque is then delivered to the transfer case and a 4-wheel drive system with front- and rear- electronic locking differentials.
Off-road performance is further enabled by proprietary damper technology that provides body control for trail running and expanded wheel travel for rock crawling. Technical details about the dampers will be released later.
Calibration testing and validation are currently underway, and the Colorado ZH2 is expected to be a truly capable off-road vehicle featuring:
- 12 inches of ground clearance
- 48-degree approach angle and 39-degree departure angle
- Top speed above 60 mph
- Ability to ascend, descend and restart on 40 percent grade
- 20 percent side slope capability
Other ZH2 specifications include:
- 6:1 gear ratio
- 6,038 lbs. curb weight (estimated)
- 7,338 lbs. GVWR (estimated)
- 133.5 in. wheelbase
- 67.4 in. track width
- 210.5 overall length
- 79.8 in. overall height
- 84.5 in. overall width (including mirrors)
- 80.3 in. overall width (tire-to-tire)
- 35 in. front overhang
- 42 in. rear overhang
- 25 ft. curb-to-curb turning radius
Military Grade Credentials
The SEMA show enables Chevrolet to gain customer feedback on ZH2’s pairing of a clean, efficient propulsion system and capable off-road technologies. The ZH2 also represents an opportunity to demonstrate this technology under the mission requirements of the U.S. military, among the world’s most demanding off-road operators.
“The Chevrolet Colorado ZH2 is part of a multiyear cooperative partnership between GM’s engineering team and the U.S. military,” said Charlie Freese, executive director of GM’s Global Fuel Cell Business. “We are putting the ZH2 to work on Army bases around the country, and it will be in the hands of real-world war fighters.”
The evaluation process will begin in early 2017.
New, off-road development track at GM’s Yuma Proving Ground
Chevrolet recently developed new off-road test areas at General Motors’ Yuma, Arizona Proving Ground.
The Yuma Proving Ground is located on 2,400 acres of land in southeastern Arizona and has 75 GM employees and 40 contractors. Opened in 2009, Yuma features a range of tracks, laboratories and courses.
The new courses feature a high-speed desert sand trails; low-speed, loose river rock crossings; and steep, technical hill climbs and descents. Yuma Proving Ground’s new off-road course will play a key role in developing future Chevrolet off-road performance technologies and vehicles.