The Ford Motor Co. and U.S. Environmental Protection Agency are joining forces to improve fuel economy. They will combine efforts to develop a hybrid, high-efficiency vehicle that uses hydraulic fluid to store and provide energy to power the car. "This is the first-ever cooperative agreement with an automobile company targeted to develop EPA-patented automotive technology," says EPA Administrator Christie Whitman. The basic technology was developed and patented by EPA's National Vehicle and Fuel Emissions Laboratory in Ann Arbor, Mich., and refined under a cooperative agreement with Ford. The advanced powertrain features a high-efficiency engine and hydraulic hybrid propulsion system. The hybrid system uses hydraulic pumps and hydraulic storage tanks to store energy. "Recognizing that significant hurdles remain in development and prove-out, hydraulic hybrid technology holds great promise," says Gerhard Schmidt, Ford Motor Co. vice president - research. In the agreement, Ford has committed to invest to further develop the proprietary technology, with an aim toward putting a pilot fleet of vehicles on the road by the end of the decade, the EPA reports. Ford and the EPA will be working with FEV Engine Technology Inc., Aachen, Germany, and Eaton Corp., Cleveland, to build and test the new technology.