With the concept of series hybrids/range-extended EVs growing in popularity, I thought it might be interesting to take a look at a study that was put out a few years ago by San Dimas, CA-based AC Propulsion. AC Propulsion constructed a towable trailer with a range-extender for their tZero prototype car. This genset was based off of a small motorcycle engine – something GM has suggested they might use for some eFlex vehicles.
AC propulsion’s used a 500cc Kawasaki engine rated at 20kW output to maintain their tZero’s battery at around 80% SOC. Without any battery supplementation, the device could achieve between 32-38 mpg. Though an interesting experiment, I think that this study was flawed in a few ways – or at least not completely applicable to future efforts.