U.S. Department of Energy - Energy Efficiency and Renewable Energy

Vehicle Technologies Office – Advanced Vehicle Testing Activity

SuperShuttle Denver Fleet: CNG Vans

Photo of SuperShuttle VansThis study was designed to evaluate the latest technology compressed natural gas (CNG) alternative-fuel vehicles (AFVs) in a real-world application. The project resulted in detailed information on operations, maintenance, and costs for running AFVs in fleet service. Because the vehicles in this fleet accumulated mileage quickly (about 70,000 miles per year), emissions testing was also conducted.

The vehicles evaluated were 1999 Ford E-350 passenger vans: five dedicated CNG, five bi-fuel CNG/gasoline, and three conventional gasoline vans. SuperShuttle Denver used the vans to shuttle passengers around the Boulder, Colorado, area, and between Boulder and Denver International Airport.

The project ran for approximately 18 months, including 12 months of data collection. The data focused on fuel use and costs, maintenance records and costs, emissions, and performance, along with subjective perceptions from SuperShuttle drivers and management on the fleet's implementation experience.

This project relied on the cooperation and support of the following participants:

  • SuperShuttle Denver: As the host fleet, SuperShuttle was responsible for purchasing and operating the vehicles, and allowing access to operational and maintenance data.
  • Gas Research Institute: GRI established a cooperative research and development agreement with the National Renewable Energy Laboratory (NREL) to conduct the evaluation and provided funds to support data collection and emissions testing.
  • U.S. Department of Energy: DOE allocated funding to NREL to manage and conduct this project.
  • National Renewable Energy Laboratory: NREL collected and analyzed the study data, and produced reports on the results.
  • Natural Fuels Company: Natural Fuels supported the CNG fuel infrastructure in the Denver metro area. The company provided fuel station access cards for each CNG vehicle and also offered fuel-pricing incentives to the fleet, as well as CNG training for the fleet personnel.
  • Ford/Sill-Terhar Dealership: Sill-Terhar was the local Ford dealership responsible for vehicle delivery and service.
  • Environmental Testing Corporation: ETC conducted emissions tests on the vehicles at prescribed accumulated mileage intervals.

Related Reports

The following documents are available as Adobe Acrobat PDFs. Download Adobe Reader.

  • SuperShuttle CNG Fleet Study Summary, March 2001 (PDF 385 KB)
  • SuperShuttle CNG Fleet Evaluation: Final Report, October 2000 (PDF 672 KB)
  • Denver SuperShuttle CNG Fleet Evaluation: Fleet Start-up Experience, May 1999 (PDF 367 KB)
  • SuperShuttle Focus Fleet Study: Interim Project Report, November 1999 (PDF 66 KB)

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