I drove the car for the rest of the weekend without plugging it in again. I ended up doing 253 miles in total, using 5.8 gallons -- plus the one battery charge -- for a total of 43.5 mpg. The car indicated 102 miles of (gasoline) range remaining when it left my driveway.
The mix of driving I did was about 75 percent highway, mostly around 65 mph but with lots of hills. The around town stuff was also very hilly. We helped the car out by not running the A/C, an easy assist given the beautiful spring weather. Given all that, the 43.5-mpg average is not spectacular. (The Volt's EPA estimates are 35 mpg city, 40 mpg highway.) A Toyota Prius could probably do better; so might a VW Golf TDI. Either would be considerably cheaper.
Clearly, if you're not going to plug in the Volt regularly, you're far better off to buy a Chevy Cruze (or most any other traditional compact) and bank the extra $10k. And as a plug-in EV, the Volt's range is less than that of the considerably less expensive Nissan Leaf. So then, what's the point? What the Volt offers is flexibility. Whereas a pure EV like the Leaf might be a family's third car, used exclusively for commuting or short trips around town, the Volt could be a second or even an only car. It's the commuter car that can also go out of town. The Volt can be driven as a pure electric car but it's far more versatile than one, because you can use it even if there might not be enough battery power to get where you're going and back home again. So it's less likely to be left in the garage and more likely to be out on the road.
Whereas a pure EV is a very purpose-specific car, the Volt can cover a much wider spectrum of use. The only area where it really doesn't make much sense -- although it could still be used -- is for long-distance driving. Run it most of the time on gasoline, and the Volt seems silly. The higher the portion of EV driving, the more compelling the Volt becomes. Chevrolet's car of the future can return fuel economy as low as 35 mpg -- or, with frequent recharging, it can never use any gasoline at all. Your mileage may vary, indeed.