Well, looks like Volkswagen won't be the only carmaker unveiling a new hybrid sedan at next month's Detroit Auto Show.

Yesterday, Mercedes-Benz revealed a pair of hybrid E-Class sedans in Germany, the first with a gasoline V-6 engine and the second with a turbocharged diesel four.

According to Autoweek, the E 400 Hybrid will reach U.S. dealers next year as a 2013 model. It's the first E-Class hybrid; so far, Mercedes-Benz has offered only the S 400 Hybrid sedan and the now-defunct ML 450 Hybrid sport utility vehicle.

Like the hybrid S 400, the E 400 Hybrid uses a single electric motor between a 302-horsepower, 3.5-liter V-6 engine and a modified version of the company's standard seven-speed automatic transmission.

But the motor in the hybrid E-Class is more powerful than the earlier model's, providing peak power of 20 kilowatts (27 hp) and a substantial torque of 184 pound-feet. The company says the E 400's 0-to-60-mph acceleration time is 6.7 seconds, with top speed limited to 130 mph.

2011 Mercedes-Benz E300 Bluetec Hybrid

2011 Mercedes-Benz E300 Bluetec Hybrid

The company's first diesel-electric vehicle, the E 300 Bluetec Hybrid, was previewed as long ago as the Geneva Motor Show in March 2010. At that point, its electric motor output was only given as 15 kilowatts.

The car we'll see next month uses a 201-hp, 2.1-liter turbodiesel engine (smaller than the Geneva car's 2.2-liter) that produces 369 pound-feet of torque and is fitted to the same 20-kw electric motor and modified seven-speed automatic as the gasoline hybrid E 400.

For the diesel hybrid, 0-to-62-mph acceleration is quoted at 7.5 seconds, and top speed is (curiously) higher than the gasoline hybrid, at 150 mph.

The E 400 Hybrid has "27 mpg" shown on its door, likely its EPA highway rating. (The larger, heavier 2012 S 400 Hybrid is rated at 19 mpg city, 25 mpg highway, for a combined 21-mpg rating.)

As for the E 300 Bluetec diesel hybrid, the prototype diesel hybrid model from 2010 was said to achieve 57.4 mpg on the European cycle (which returns numbers 20 to 30 percent higher than U.S. EPA mileage figures).

Both E-Class hybrid models use a 0.8-kilowatt-hour lithium-ion battery pack located in the trunk. Under light loads and at speeds under 35 mph, Mercedes-Benz claims that each car can propel itself electrically for less than 1 mile.

2011 Mercedes-Benz E300 Bluetec Hybrid

2011 Mercedes-Benz E300 Bluetec Hybrid

Other fuel-efficiency modifications include a "sailing mode" that decouples the engine from the gearbox to power the car electrically at speeds up to 100 mph, low-rolling resistance tires, aerodynamic modifications, and of course the regenerative braking and start-stop features of all full hybrids.

Both E-Class hybrids will be officially launched in Detroit, though only the gasoline E 400 Hybrid has been confirmed to go on sale in the U.S.

Keep an eye on these pages for all our 2012 Detroit Auto Show coverage. As we count down the days and weeks leading up to the show, more cars, concepts, and other new items are sure to emerge.


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