By Andrew Ganz
Monday, Jan 9th, 2012 @ 6:04 pm

Mercedes-Benz has unveiled its E400 Hybrid at the North American International Auto Show. The addition of the hybrid system is expected to net the mid-size luxury sedan a combined fuel economy rating of 27 mpg.

Early next month at the Detroit auto show, Mercedes-Benz will unveil its first-ever midsize gasoline-electric hybrid, a model expected to net a combined 27 mpg figure.

The E400 Hybrid starts off with the E350′s 3.5-liter V6 gas engine and then adds a brushless electric motor and a 0.8 kWh lithium ion battery that add an additional 27 horsepower and 184 lb-ft. of torque. Since hybrids require the use of some fuzzy math, that means that the combined output should be around 325 horsepower 400 lb-ft. of torque — figures that give it a 0-60 sprint of just 6.7 seconds.

A seven-speed automatic transmission plucked from the standard E350 puts power to the rear wheels, while an automatic start/stop system eliminates fuel consumption and emissions while the vehicle is at a complete stop. Meanwhile, regenerative braking captures otherwise lost energy to recharge the battery. Mercedes-Benz has not stated just where the battery is located, but we anticipate that it will be wedged in behind the rear seatbacks in the trunk area.

Surpassing the E350 BlueTEC diesel as the most efficient E-Class offered in the North American market, the E400 Hybrid will boast an EPA fuel economy rating of 24 mpg in the city and 31 on the highway. Those figures are the best you’ll find on an E-Class, but they don’t quite match the Infiniti M Hybrid’s 27/32 mpg numbers.

Mercedes-Benz hasn’t priced its newest model, but it seems reasonable to figure that it will run somewhere north of the E350 BlueTEC’s roughly $52,000 figure given the added performance and technology, not to mention the reduced fuel consumption.

While Mercedes-Benz led the charge into the full-size luxury segment with its S400 Hybrid, the E400 Hybrid is actually pretty late to the party. Lexus has been the segment’s longest player, but Infiniti recently offered up a hybrid version of its M and BMW is planning a 5-Series ActiveHybrid soon for the North American market, a region that has proven to be friendlier to hybrids than diesels.

The E400 Hybrid is expected to go on sale late next year in the United States.