Let's get one thing perfectly clear: the 2011 Chevrolet Volt does NOT have a direct mechanical connection between the engine and wheels. Ever since a report last week in the Telegraph indicating that the Volt/Opel Ampera could drive the wheels directly at highway speeds, this controversy has started to bubble up.
After HybridCars.com spoke with GM spokesman Rob Peterson, the waters were simply muddied further. The site's editor asked Peterson a hypothetical question about what could be done to maximize the Volt's efficiency. Unfortunately, some context was left out in the write-up of Peterson's response. AutoblogGreen checked directly with Peterson on Tuesday evening. The question was essentially this: if driving the wheels directly the way current hybrids do could improve efficiency, would that be possible in the Volt. Peterson told ABG that in general, the engineers would do whatever they felt was necessary to maximize efficiency including direct-drive if they thought that was the answer.
However, the basic architecture of the Voltec powertrain has not been changed since it debuted in 2007 and the engine is only connected to the generator. There is currently no mechanism to drive the wheels even if the engineers wanted too. If they felt that was the best solution, they would have to re-engineer the entire drive system. Having said that, there are control strategies originally developed as part of the two-mode hybrid program that are in use in the Volt and lessons learned from other development efforts have been applied to this new car.
As for the case of Andrew English of the Telegraph in the UK, apparently a technician whose job is to take care of the cars and shuttle them around was the source of the original erroneous story. The technician was not actually familiar with the inner workings of the Voltec system and was not authorized to speak about it.
Ultimately, this all comes down to people's obsession with labels. If we didn't insist on categorizing everything, it's likely none of this would have ever come up because in the end it only matters if the system works.