Ford is advertising the third-generation Fusion as “America’s smartest midsize sedan.” To back that claim, the manufacturer is loading each unit with the MyFord Touch infotainment interface and a long list of advanced safety features — including blind-spot detection and lane-keeping assistance — that are rare for the segment. But the Fusion looks smartest at the pump: The gas, gas/electric hybrid and plug-in hybrid are expected to lead their classes in fuel efficiency.

The leanest gasoline engine is the 1.6-liter EcoBoost turbo, an inline four that is projected to 26 mpg in traffic and 37 mpg on the highway. Buyers also can choose between two other four-bangers that offer fewer miles to the gallon but a significant boost in horsepower: The Fusion’s standard, 2.5-liter, naturally aspirated iVCT and a 2.0-liter EcoBoost turbo are projected at 22/33 and 23/33, respectively.

The Fusion Hybrid pairs the 2.0-liter turbo with an electric motor and lithium-hybrid battery pack to earn a projected 47 mpg city and 44 on the highway. The Fusion Energi uses the same combination with a plug-in battery to achieve 100 miles per gallon equivalent or “MPGe,” which edges out the Chevrolet Volt’s 92 and the Toyota Prius plug-in’s 87.

The aforementioned safety features are joined by electric-assisted power steering, adaptive cruise control and a parking-assist system, and the slightly longer and wider body now rides on a stiffer platform.

The new Fusion’s appearance was overhauled with more curvaceous sheet metal and a yawning black grille and lower-fascia inlets to replace the heavy chrome face that distinguished the second-generation model. The interior was revamped as well, but retains a simple, elegant look with hard black plastics and brushed aluminum accents.

Other standard equipment on the base model includes navigation, Bluetooth and iPod compatibility. The SE edition adds satellite radio and pimp-approved, 18-inch gloss black wheels, and the Titanium trim level adds a rear spoiler and 19-inch polished alloy wheels.

Prices for the gasoline Fusions range from $21,700 for the base to $30,200 for the Titanium edition. The Fusion Hybrid lists for $27,200; MSRP for the plug-in hybrid, which should be available before the year is out, has yet to be determined.

The 2012 Ford Fusion was selected as Fleet Car of the Year. Click here to read more.

To see more articles from Business Fleet's 2012 July/August magazine issue, click here.