ANN ARBOR, Mich — EPA officials say a technology patented by the agency and dubbed the hydraulic hybrid system could give U.S. manufacturers an edge with increasingly fuel-conscious car consumers, according to a report by The Detroit News. The system uses hydraulic pressure to recapture energy lost through braking, then releases the pressure during acceleration. The EPA estimates hydraulic hybrids could improve fuel economy up to 55 percent, versus 30 percent to 40 percent for a conventional gas-electric hybrid. The agency believes that in some ways, hydraulic hybrids will be superior to gasoline-electric hybrids, such as the Toyota Prius and Ford Escape Hybrid. One big advantage: they cost less, meaning consumers will see a more immediate financial payoff. If the plan to transfer the technology from a test lab to the private sector works, it would be a first for the EPA. Officials say this is the first concrete signal that the agency's research and development efforts will be more focused on commercial applications than basic science. The EPA is working on pilot projects with Ford Motor Co., the U.S. Army, Eaton Corp. and United Parcel Service to get the technology into the real world as quickly as possible. In fact, the agency has already created a prototype for a hydraulic hybrid version of the Ford Expedition, and UPS expects to use a hydraulic hybrid truck in the spring. Because of the added weight of the tanks used to store pressurized fluid in the system, engineers expect the best application for hydraulic hybrids will be in heavy-duty trucks such as UPS trucks that start and stop a lot in city driving.