My Wife & I are admittedly in the Volt's sweet spot, we don't need it for long drives, we live in GA (generally pretty warm), don't need it for motorsports, but despite buying it in early Dec 2012 (5 months ago) & therefore only having only a winter to it's name so far, here's what it's done -
It's up to estimating 53 electric-only miles out of the current charge (epa rated @38). It's done 4897 miles out of 5048 on electric. We haven't opened the gas cap yet.
When we first sat in it at the dealer's & turned the car on, it fired the gas engine up & performed maint mode which I estimate burned 1 gal (w/the car in 'park' the whole time). Additionally, although it's a guess, from the car's gas ga. the tank wasn't full, I estimate it had ~8 gal. On the first day I was putting it in mountain mode (which chews up gas/kills mileage) testing out/learning the technology in the car & because these don't happen anymore plus the fact that warmer weather is emerging, we're expecting miles per charge & miles per gallon to get even better. If the car had 8 gals to begin w/ & has 3 now then 5048mi/5gal = 1009.6mpg. It's my fault it's so low & we're hoping to get to 10,000 or so before too long. Electric costs us about 8.5c/kwh & the car's costing pessimistically 2 cents a mile to drive electric.
We'll never buy another gasoline car again.
I like what Toyota's done w/the Prius but for me 50mpg is Wayy too low. I do wonder if public perception will catch up before end of days tho & hoping to have an impact is why I post all this.
Thanks GM for the best car the world's never seen.