It's not known whether the prototype's internal combustion component will be a gas- or diesel-powered engine, but Andrew Frank, a professor at the University of California-Davis who is credited with developing the first plug-in hybrid, believes it's likely to be a series hybrid rather than the more common parallel-type hybrids that are sold today. This means that the internal combustion engine on board will not be directly attached to the drivetrain, but act merely as a generator to fill the batteries up with juice when they're low. This advanced technology is common on large locomotives, and some have suggested it will be used in the future on heavy duty pickups to greatly increase torque ratings.
If GM's listening, we say go with a small on-board diesel motor and really wow the crowd with an extended driving range that makes the Prius look like a gas-swilling pig. We should learn more about the technology that GM will be using in this prototype at the Los Angeles Auto Show later this month where Rick Wagoner is scheduled to give a speech.
[Source: The Detroit News]