There is a vast gulf between a HEV (Prius) and a PHEV (Volt). The energy source of a Prius is 100% gasoline; the energy source for a Volt should be about 80% grid electricity and 20% gasoline, depending on your driving habits. It's much closer to an EV1 than to a Prius.
Based on what proven data? How do we know how people will use their serial hybrids?
I am dubious that the serial-hybrid owners would have them plugged in as much as the serial-hybrid pundits are suggesting.
What if people don't have easy access to power plugs where they go?
What if they don't have enough time on the plug to get their batteries fully recharged in time? (It can be quite a while for a 120v 12amp plug)
..."Oh, I forgot to plug in the Volt last night... Oh well, I have plenty of gas in the tank"...
Plus, the serial hybrids may have an ICE generator that is too small to provide full eMotor power when the batteries run down. I suppose it will incent people to find a power plug if their performance degrades substantially when the batteries are run down, but it is going to make long trips unpleasant. I used an example of the Tesla "demo drive" (bay area to Lake Tahoe) with a serial hybrid. If the batteries run down just as you get to the steep grade of highway 80 you are going to be limited by the max power of the ICE to get you up the hill, hopefully with the passing power you need. The Volt appears to be planning a ~70hp ICE, ~160hp eMotor. So when the batteries are exhausted you will be limping at ~half power until you get to a plug. People on the Tesla blog are saying that you only need 10-20hp in the ICE to be able to maintain highway speeds... that would seem sadly underpowered if you ever run the batteries down.
Tesla has been about "no compromises" and I can't see them selling a luxury sedan that goes into "limp" mode after ~40-80 miles of battery power. The alternative is to install a big, powerful ICE that will add a lot of weight and hurt efficiency & battery only range.
I wonder what kind of ICE and eMotor Fisker plans. I wonder what performance they will have with batteries full and batteries empty.
I think they plan to
give details next month at NAIS in Detroit.
(I am waiting to see if Fisker and Tesla are somehow to be interconnected in some way)