Al notes a story in Technology Review reporting on a CMU study (now over a month old) claiming that the Volt doesn't make economic sense, and GM's response. The study suggests that hybrids with large batteries offering up to 40 miles of range before an on-board generator kicks in simply cost too much for the gas savings to work out (PDF). Al writes: "Unsurprisingly, GM disputes the claims, saying 'Our battery team is already starting work on new concepts that will further decrease the cost of the Volt battery pack quite substantially in a second-generation Volt pack.' Interestingly, however, GM admits that the tax credits for plug-in hybrids will be crucial to making the volt successful. Without those credits, would an electric vehicle like the Volt be viable?"