Ford claims that the 2013 plug-in hybrid Fusion Energi will be rated at 100-plus MPGe.

Among Ford's various available powertrain options for the recently unveiled 2013 Ford Fusion is the plug-in hybrid Fusion Energi, a vehicle that Ford claims will be the "most fuel-efficient midsize car in the world." The Fusion Energi is on a fast production schedule, officially launching in fall 2012.

Essentially, the Fusion Energi is a plug-in version of the 2013 Fusion Hybrid. The Energi features a 2.0-liter Atkinson-cycle four-cylinder gasoline engine and a lithium-ion battery pack of undisclosed capacity. So far, Ford only released this brief statement pertaining to the Fusion Energi:

"Topping the fuel-efficiency ladder is the Fusion Energi plug-in hybrid, aiming to be the most fuel-efficient midsize car in the world. Arriving this fall, Fusion Energi is anticipated to deliver more than 100 MPGe, a mile per gallon equivalency metric for electrified vehicles. This is 8 MPGe more than the Chevrolet Volt and 13 MPGe more than the projected efficiency of the Toyota Prius plug-in hybrid model."

The 2013 Ford Fusion Energi is expected to launch in fall of 2012.

Ford has not released any of the Fusion Energi's key specs, such as all-electric range, charge times, price and so on. The company is allowing one number to do all the talking: an expected 100-plus MPGe (miles per gallon equivalent) in a full-size sedan. If Ford hits that mark, and prices the Fusion Energi to beat the Chevy Volt and at least to match the Prius Plug-in Hybrid, then Ford's only problem could be making enough to meet demand.