Eaton, a company primarily known for making superchargers that make your vehicle go like stink, but guzzle even more gas, is also in the series hydraulic hybrid
(SHH) business. The drive system in a hydraulic hybrid replaces the conventional drivetrain; the engine is effectively rendered a "pump" for the hydraulics, and energy is stored in two different accumulators that then power the wheels. Fuel savings of 50-70% are achieved by the system being much lighter than a traditional drivetrain, along with regenerative braking and the fact that the engine can be turned off when stopped and when decelerating.
The first real-world application of Eaton's SHH will be in a number of UPS delivery trucks
next year. No auto manufacturer has any plans to create an SHH -- because of the lack of batteries, when the engine is cut off, electrical systems like the radio and climate control are also shut down. Eaten has a cooperative working agreement with the EPA
to develop its hydraulic hybrid system, and has selected IBM to develop software
to refine the system. Thanks for the tip, Gavin!