At lot has changed with the Chevrolet Volt since it was first shown in concept form at the Detroit Auto Show in early 2007. Gone is the swoopy bodywork (which was deemed elegant, yet not aerodynamic enough), support for E85 fuel (the Volt now requires premium), and the gas tank was cut in size from 12 gallons to less than 8 gallons.

One thing that remained constant through this constant state of change with the Volt program over the past three years has been the electric driving range of the vehicle. General Motors has always stuck to a 40-mile range for the vehicle on battery power alone. Now, however, GM has revised the battery range to "25 to 50 miles" according to the Associated Press.

GM spokesman Rob Peterson says that the revised range figures come as a result of extended testing including operating the Volt in extreme temperatures. Other factors that will come into play include whether the driver is traveling on flat or hilly roads, whether the HVAC is operating, or if the driver has a lead foot.

By stating this change now, GM may avoid complaints from customers in the future who don't achieve the previously stated 40-mile battery range. On the flip side, Volt owners who drive on absolutely perfect/level roads, don't run the AC, and drive miserly can at least be delighted at the potential for 50 miles of battery-only travel.

The additional driving range provided by the gasoline engine/generator remains the same at 300 miles.

GM expects to build 10,000 Volts by the end of 2011 at a cost of $41,000 each (before a $7,500 tax credit). The company hopes to boost production to 30,000 the following year.

The Volt will be joined at a later date by the Volt MPV5 which offers a crossover body style and seating for 5. GM stated that that the vehicle would have an electric driving range of 32 miles at its announcement – there's no word on what the revised figure will be once it reaches production.