I call BS on 200+ MPG. I guess if you never drain the battery, then MAYBE (with putting around a level parking lot or neighborhood). But there is NO WAY that sort of mileage is happening in that piece of crap with the gasoline engine running. Period.
No doubt that if I work 25 miles from home I will just plug into my employer-provided charging station while Im working.
When gasoline is providing the power, the Volt might get as much as 50 mpg. But that mpg figure would not take into account that the car has already gone 40 miles with no gas at all.
So let's say the car is driven 50 miles in a day. For the first 40 miles, no gas is used and during the last 10 miles, 0.2 gallons are used. That's the equivalent of 250 miles per gallon. But, if the driver continues on to 80 miles, total fuel economy would drop to about 100 mpg. And if the driver goes 300 miles, the fuel economy would be just 62.5 mpg.
http://money.cnn.com/2009/08/11/autos/volt_mpg/?postversion=2009081108