Sources tell us GM CEO Fritz Henderson will announce today the Chevy Volt extended-range electric vehicle will receive a city fuel economy rating of 230 MPG from the EPA when it hits showroom floors later next year. Holy game-changer, Batman!

This story's still developing, but if our sources are correct, it would blow the Toyota Prius out of the water. Heck, it'd blow every other vehicle currently on the market out of the water with the exception of the Tesla roadster โ€” and that's no four-door mid-size sedan. So for GM this represents a huge marketing coup โ€” the ability to claim the most fuel efficient vehicle in the world and a big blow to detractors who claim the big, sweaty 'merican manufacturer can't build quality products.

We'll have more out of GM's Warren Technical Center as the General holds their big product showcase event throughout the day.