The Volt is more eficcient and less polluting than the Leaf, Tesla, or any pure-EV could ever be. Let me explain.
Any EV out there is somewhat range-limited. This means that you need a separate, ICE-car for every time you might possibly exceed you car’s range, whatever range that might be.
Now, I’d draw a line in the sand at about 10-15 days a year, beyond which it’s simply too much of a PITA to keep renting a second car…you just BUY a second car. Realistically, this makes an EV 1/2 of a “two-car transportation strategy”: you buy a Leaf, you also keep a Malibu on standby.
So, owning an EV means you need TWO cars; room to park them; TWO annual inspections, registrations, etc. This is less “green” in many ways than one newer plug-in hybrid…including the sort of “green” that you fold in half and put back in your pocket!