Chevy's still pending Volt is being touted as getting 230 MPG. However, that's ONLY based on city driving. Depending on the situation, mileage could even drop below 50 MPG.
That's all fine, however who is going to pay an extra $9000 for the same mileage they can get in a Prius. Of course the government will fix that by giving taxpayer money in the form of rebates to Volt purchasers. Since the government now has a vested interest in making sure their auto company succeeds (not by selling cars most people want, but by selling cars the government likes), it will pump our taxpayer money into GM for the rest of eternity since GM cannot ever be competitive with the business model they've been given by the current administration.
The other question I still have regarding the mileage touted for plugin hybrids - I haven't seen any evidence that the mileage calculations take into account the electricity used to charge these vehicles when they are plugged in. Yes it's possible that KWH's are taken into acount in the figures, and it's possible that even factored in, the energy efficiency is still an improvement, but on the face, it seems that the promotors of plugin vehicles are content to believe that battery charging uses no energy while plugged in.
I would love to hear from anyone who has more information on this last point.