Ran across this recently... http://www.mobilehydraulictips.com/hydraulic-hybrid-vehicles-future-driving/ Peugeot apparently has a hydraulic hybrid car in development... http://www.extremetech.com/extreme/146450-peugeot-unveils-hydraulic-air-hybrid-80-mpg-car From what I've read from Wikipedia and other sources this technology is simpler, less expensive, more energy efficient, and requires less toxic materials then electric hybrids. What's the down side? Why have we spent the last 20 years developing electric hybrids instead of this? Is it just a marketing problem? No ones figured out how to make hydraulic equipment sound sexy?