WASHINGTON - The U.S. EPA and Chrysler have signed an agreement to develop and adapt hydraulic hybrid technology for large passenger cars and other light-duty vehicles. The automaker’s and the EPA’s goal is to design a Chrysler Town & Country minivan as a demonstration vehicle, using the patented technology developed by the EPA, and test the vehicle in 2012.

The EPA said it anticipates that use of this technology in light-duty vehicles will increase overall fuel efficiency by 30-35 percent, 60 percent city driving, and reduce overall greenhouse gas emissions by 25 percent.

Chrysler stated the research project will focus on adapting the hydraulic hybrid system to a Chrysler Town & Country minivan equipped with a 2.4-liter, inline four-cylinder gasoline engine. EPA said a joint engineering team will design and integrate the hydraulic hybrid system into the minivan. The minivan will feature a unique powertrain that replaces the automatic transmission, EPA stated.

Components of the hydraulic hybrid system include a 117 cc engine pump, a 45 cc drive electric motor and a two-speed automatic transmission. Fluid for the system will be stored in a 14.4-gallon high pressure accumulator.

The hydraulic hybrid system captures and reuses the energy lost in braking through a hydraulic pressure vessel. According to Chrysler, the system produces power with engine torque driving a hydraulic pump that charges the high pressure accumulator of up to 5,000 p.s.i. The high-pressure accumulator delivers the pressure energy to the axle hydraulic motor, giving the vehicle power to drive the wheels. The gas engine will remain off if the accumulator charge is sufficient to drive the motor.

EPA’s work for this project will take place at the National Vehicle and Fuel Emissions Laboratory. Other engineering partners working on this project include FEV of America, Inc. of Auburn Hills, Michigan and Southwest Research Institute of San Antonio, Texas and Ann Arbor.

More information on the hydraulic hybrid system is available at epa.gov/otaq/technology.