Obviously the Volt can be driven without gas, in fact that the whole purpose. The range extender exists only for if you have to go further than 40 miles between charges.

One thing to consider is what would happen if the car ran out of gas after the battery has reached its depletion point, or was in charge-sustaining mode. Since there would still be charge in the battery, it is conceivable that the car could be engineered to dip into that a little and give the driver a "limp-home mode" that might allow 1 to 2 miles of slow driving to get you to the gas station.

The New York Times has just reported that Volt executive Frank Weber mentioned such a limp home mode might be available on the Volt.

Or will it?

I just recently had asked this same question to Mr. Weber's colleague, Bob Kruse, who is GMs director of Hybrids and EVs.  My questions and his comments follow:

Will there be a limp home mode, if you run out of gas at the same time you're at battery depletion, allowing the driver a couple of miles of low speed driving?
If it's your Volt, are you willing to wound your battery for that convenience?

If it happens very rarely it may not impact the cells longevity.
Well I'm the expert on that and is that something that you're willing to sacrifice, the longevity of your battery in order to overcharge it?

Ideally no, but I think if it were a dire situation the car could give you a big red button on the screen...I could let you do it but you can't expect me to give you a life of the car battery of you want to operate outside the norms. But we do have Onstar so if you use it they'll bring you a gallon of gas.  I don’t know whether were going to do it (have this feature) or not.

So it looks like this idea is probably still up in the air.

Would you want this feature?