The 2011 Chevrolet Volt made major media waves when it was first revealed that its engine could power the drive wheels independently under certain circumstances. According to a report from HeadlineAuto in the UK, though, General Motors' European division is actually considering adding a switch for the Opel Ampera (the Volt's more attractive European cousin) that would allow the driver to control how the drivetrain operates.
For instance, when driving longer distances, such as when traveling from city to city, the driver could potentially switch the car into its so-called charge sustaining mode so that the gasoline-powered engine would run constantly in order to maintain a full charge of the battery. Then, after the speeds slow back down and the driver re-enters an urban area, the car could be put back into its normal battery-first mode.
At this point, this report appears to be little more than speculation based on statements made by GM's Lars Peter Thiesen, who is overseeing the process of tuning the Opel Ampera for the European market. There's currently no reason to believe that GM would make such a modification to the U.S.-spec Volt.