Musk, responding to a question posed by Lyle Dennis at GM-Volt on his feelings about the range-extender concept behind the Chevy Volt and why he's not considered it it any Tesla products, says:
We looked closely at a range extender architecture for Model S. It ends up costing about the same in vehicle unit cost, a lot more in R&D and a lot more in servicing. Also, although performance is ok when both battery and engine are active at the same time, it turns really bad when the battery runs out and an undersized engine is carrying all the dead weight of the pack. Essentially, a REV is neither fish nor fowl and ends up being worse (in our opinion) than either a gasoline or pure electric vehicle.
That'd be perfect, make it clear you looked at the idea for the Tesla Model S Sedan and dismissed it after a simple cost-vs-return analysis, then pivot into a positive statement about your product. Musk, who's not yet figured out the best way to go after the competition is by talking flowers, sunshine and honey publicly, saving the knife-and-dagger treatment for his PR team during after-party drinks with the press later on, should have just left it there. He didn't.
An important consideration that people without a technical background don't understand is that you can either have a high power or a high energy cell chemistry, but not both. Since the battery pack in a plug in hybrid like the Volt has to generate the same *power* as a much larger battery pack in a pure electric vehicle, it has to use a low energy cell chemistry.
So, is he saying GM's Volt engineering team lack a technical background or is he saying potential customers lack a technical background? Unknown. Either way, he probably should have left it with just the "REV doesn't make sense" comment. Lesson learned? [GM-Volt]