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Clean Automotive Technology

Demonstration Vehicles

EPA, in cooperation with its partners, has successfully installed and tested hydraulic hybrid technology in a variety of vehicles. These demonstration vehicles, featured below, have shown tangible real-world results, including fuel economy improvements of 30 percent to over 100 percent over their conventional counterparts.

View information on hydraulic hybrid work truck View information on hydraulic hybrid large SUV View information on hydraulic hybrid delivery truck View information on hydraulic hybrid yard hostler View information on hydraulic hybrid light-duty vehicles


Full Series HHV in a UPS Delivery Vehicle

On June 21, 2006, EPA and its partners announced the world's first series hydraulic hybrid urban delivery vehicle. This vehicle is a promising part of the solution to the growing energy crisis. This revolutionary vehicle underwent real world testing by UPS in 2006 and 2007 and had encouraging results.For more information on the specific layouts please visit HHV Layouts.

This vehicle:
  • Achieved 60-70 percent improvement in fuel economy
  • Has an estimated 2-3 year payback when produced in high volume
  • Partnerships with Eaton, UPS, Parker, International Truck and Engine corp., the US Army, FEV, Morgan-Olson and Southwest Research Institute
  • Undergoing real world tests by UPS
  • Won an award for hybrids in the 2007 Michelin Bibendum Challenge in Shanghia, China

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Series Hydraulid Hybrid Yard Hostler

A yard hostler is an off-road truck used to transfer cargo containers at marine ports, rail yards, warehouses and distribution centers. EPA in cooperation with APM Terminals, Parker-Hanniffin, Kalmar Industries, R. H. Sheppard Co., Webasto, FEV, the Port Authority of New York and New Jersey, Port of Rotterdam, and the New Jersey Department of Environmental Protection created this highly-efficient yard hostler using hydraulic hyrid technology. This HHV is estimated to:
  • Improve fuel efficiency by 50-60 percent
  • Reduce maintenance and operation costs
  • Reduce emissions and climate change greenhouse gases by over 30 percent

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 Series hydraulic hybrid yard hostler demonstration vehicle.

Full Series HHV In A Ford Expedition SUV

This hydraulic hybrid was built to demonstrate the fuel savings that result from combining a full series hydraulic hybrid system with a diesel engine. The prototype was installed in a 2003 Ford Expedition SUV. This vehicle was announced and displayed to the public in 2004 SAE World Congress. The results were remarkable:
  • 85 percent improvement in fuel economy with a diesel engine
  • Less than two year payback when produced in high volume
  • Expected net lifetime savings from $4,000 up to $6,000 from fuel costs and brake maintenance
  • Displayed excellent performance

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Parallel HHV In A Ford F-550

This Ford F-550 parallel hydraulic hybrid vehicle was built to demonstrate the benefits of parallel hydraulic hybrids and to examine the cost-effectiveness of parallel systems. This HHV:
  • Demonstrated the ease of retrofitting trucks with hydraulic hybrid technology
  • Achieved a 20-30 percentimprovement in fuel economy
  • Won a Gold award for mpg improvement and a Silver award for performance at the 2003 Michelin Bibendum Challeng.

    Awards for parallel F-550 hydraulic hybrid vehicle.

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 Parallel hydraulic hybrid F-550 demonstration vehicle.

Full Series HHV in a Passenger Car Test Chassis

In the 1990s, the Partnership for New Generation of Vehicles was established to help U.S. automakers design a family-sized sedan that could achieve 80 mpg. A team of engineers working at EPAs National Vehicle and Fuel Emissions Laboratory in Ann Arbor, Michigan, succeeded in meeting this goal by using a revolutionary type of hydraulic hybrid. The chassis shown at right represents a large car platform, like a Taurus or Impala.

NOTE: You will need Adobe Acrobat Reader, availablie as a free download, to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.


This HHV:
  • Achieved 80+ mpg on combined EPA city/highway driving cycles
  • Achieved 0-60 miles per hour in 8 seconds
  • Used a small 1.9 liter diesel engine
  • Showed no need for expensive lightweight materials to improve fuel economy
  • EPA estimated that in high volume the hydraulic components would only add $700 to the base cost of the vehicle and would pay for itself very quickly
  • The unique design did not use exotic or toxic materials that are difficult for manufacturers to dispose of
  • This demonstration vehicle led to several cooperative R&D partnerships, as well as licensing agreements with industry partners who want to explore adapting this cost-effective technology to the market
    Report: Progress Report on Clean and Efficient Automotive Technologies Under Development at EPA: Interim Technical Report (PDF) (198 pp, 2.5MB, EPA420-R-04-002, January 2004)

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 Series hydraulic hybrid sedan demonstration vehicle.

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