TL;DR: Driving electric is sublime and among the 3 you listed, only the Volt lets you do it for a significant number of miles. Disclosure: extremely satisfied

TL;DR: Driving electric is sublime and among the 3 you listed, only the Volt lets you do it for a significant number of miles. Disclosure: extremely satisfied 2013 Volt owner here. I test drove every form of electric-augmented automobile available for sale in the midwest (some plug-ins are for sale only on the coasts, so don't have trained repairmen near me). The C-Max had a useful form factor. It would fit my family with legroom in the rear, although the energi's trunk space was severely compromised by the extra battery. Loading groceries would block the lower 30% view. The C-Max's engine was noisy, annoyingly so. Also, Ford was caught misrepresenting their MPGs and had to readjust them. I drove a C-Max and a C-Max energi (the plug-in). Between the two, I'd prefer the energi because it runs 100% electric some of the time (but nowhere near what the Volt can do), but the price difference was not justified. www.gm-volt.com is a great resource for prospective and actual owners. From there I learned that buying a used Volt was a good idea and a great deal for these reasons: 1) used Volt prices are outrageously low for a high-quality car, albeit compact. 2) Reading the dash computer's "lifetime mpg" will let you know (with some reverse math) how many of the miles on the odometer come from the combustion engine vs electric. This is important because a Volt with 30K miles may only have 10-12K miles on gas; the rest electric. And since the electric drivetrain has a 8yr/100,000mi warranty, you're covered. 3) There are guys reporting their Volt's battery still taking 90% of their original charge after reaching 100,000 miles. 4) The guys taking ownership of the 2016 Volt are reporting 50-60 miles all-electric range and quite a bit more punch when putting the pedal down. edit: Added TL;DR