New hydraulic hybrid technology developed by EPA and Ford.

2004 Vehicles with the potential for dramatic improvements in fuel efficiency, performance, and cost-effectiveness due to new advancements in hydraulic hybrid technology have been achieved through a strategic partnering between the Ford motor company and the U.S Environmental Protection Agency (EPA).

In late 2001 the EPA developed a hybrid, high efficiency vehicle using a hydraulic launch assist system (HLA).

Initial tests on the proof of concept chassis has since led to remarkable progress with the release earlier this year of a Ford F-550 commercial demonstration vehicle at the 2004 World Congress of the Society of Automotive Engineers in Detroit.

The hydraulic launch assist has a regenerative braking system that can reportedly improve fuel efficiency by 25 to 40 percent whilst also reducing emissions.

It works by recovering some of the energy wasted as heat by the vehicle's brakes when slowing. This energy is harnessed and used to propel the vehicle the next time it needs to accelerate.

The hydraulic system offers great advantages for vehicles operating in stop and go conditions because the system can capture large amounts of energy when the brakes are applied.

The original EPA hydraulic hybrid chassis successfully demonstrated that a typical diesel or petrol powered vehicle can be fitted with hydraulic components as a secondary energy storage system. The hydraulic components work in conjunction with the primary. Making up the main hydraulic components are two hydraulic accumulator vessels which store hydraulic fluid compressing inert nitrogen gas and one or more hydraulic pump/motor units.

Benefits of the hydraulic launch assist system not only include 25-45 percent improvement in fuel economy for city driving and reduction of emissions by 20 to 30 percent but also better acceleration, less braking maintenance and reduced operating costs. It can also provide high torque quickly, even at low speeds.

Because the HLA system offers greater advantages for vehicles operating in stop and go conditions the first production models will be urban delivery trucks and pickup trucks. Other attractive applications include school buses and waste disposal trucks.

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