New Ford Fusion 2013

Later this year, Ford Motor Co. will launch this: the 2013 Ford Fusion midsize sedan in three variations — including a plug-in hybrid that gets 100 mpg, besting every other liquid-powered vehicle for sale to the American public. It could be a winning equation, but there's a few key variables Ford hasn't revealed.

The current Fusion has turned into a mainstay of Ford's lineup, and the most popular car built by an American automaker, with sales hitting 248,067 in 2011. For its redesign, Ford will run the same play it's called on with the smaller Fiesta and Focus −- build one version of the Fusion for sale worldwide, using the Mondeo name in Europe and elsewhere, to lower costs while raising quality. Assembled in Mexico and Michigan, styled in Europe to follow the new Ford global look, two of its three engines will be built in Spain and England.

All three of those engines will be four-cylinder units, in line with the trend among downsized motors for midsize sedans. The base 2-liter four returns with 170 hp and 170 lb.-ft. of torque; the top engine is now a 2-liter EcoBoost turbocharged plant with 237 hp and 250 lb.-ft. of torque — a step down from the top 3.5-liter V6 offered now.

The middle engine is a 1.6-liter EcoBoost turbo — a tiny engine for a midsize sedan, but one capable of 179 hp and 172 lb.-ft. of torque. Ford expects that model to hit 26 mpg in the city and 37 mpg on the highway, which should top the class. Ford will also aim to entice buyers with technology, such as an automated lane-keeping system and voice-controlled entertainment.

Of those 248,067 Fusions sold last year, just over 10,000 were Fusion Hybrids, which while garnering praise for handling cost several thousand dollars more than a regular version. Ford says thanks to a new lithium-ion battery pack and a smaller 2-liter engine, the Fusion Hybrid should get 47 mpg in city driving and 44 mpg on the highway, good for substantial bragging rights over the Toyota Camry and Hyundai Sonata hybrids.

But it's the plug-in version, named the Fusion Energi by Ford's Department of Redundanci Dept., that can achieve the equivalent of 100 mpg — 8 better than the Chevy Volt, and 13 mpg more than the Toyota Prius plug-in hybrid. But Ford disclosed no other details about the plug-in — such as how far it can travel on electricity alone, how big its battery pack will be and just how much it will cost.

That number will be the key to whether the Fusion Energi might be positioned as a plug-in hybrid for the masses or just another expensive science project. Ford's all-electric Focus just going into production has a sticker of $39,995 before a $7,500 federal tax credit. If the Fusion Energi has a similar price, the vast majority of Fusions sold will drive on hydrocarbons rather than electrons.