A few months back, this article in the Telegraph caused a stir among the Volt followers. In it, Andrew English quotes an Opel engineer working on the Ampera (Euro Volt):
"We are considering driving the wheels directly from the petrol engine," says Andreas Voight, an Opel project engineer.
Then, The Car Connection, wanting a clarification, went to GM and asked about this. GM responded with two points:
"We're definitely not making any changes,"
and
Peterson also directly refuted English's claims regarding the Volt's high-speed need for the gasoline engine, stating that during the 40-mile electric-only range, there is no circumstance under which the gasoline range extender will turn on--no matter the power draw or speed. Beyond that range, it supples ample power for the electric motors, whatever the driving conditions.
Now, the "no changes" comment is a bit of a red herring, because the original article was under the misconception that the planetary gearset link between the engine and axles was new. So GM was able to give a correct answer to the wrong question.
But on the more direct question, GM appears to have claimed that the gasoline engine will not be needed in the first 40 miles, and that it supplies "ample power... whatever the conditions".
It is possible that in the testing and calibration optimization work late in the program, that GM's powertrain engineers discovered that they couldn't meet certain requirements (highway acceleration?) unless they blended in some good old fashioned fossil fuel-to-the-rubber torque. In which case, GM wasn't trying to mislead, they just didn't know yet.
