The two hybrids are the gasoline-electric 2013 Mercedes-Benz E400 Hybrid and the diesel-electric Mercedes-Benz E300 Bluetec Hybrid, and for now only the E400 Hybrid will be offered in U.S. showrooms.
European buyers on the other hand will get the E300 Bluetec Hybrid early next year, which will be offered in sedan or wagon bodystyles.
Both cars feature Mercedes’ new intelligent modular hybrid concept, which essentially pairs a 27 horsepower and 184 pound-feet of torque brushless electric motor with an internal combustion engine by integrating it into the gearbox, in this case, a modified seven-speed 7G-Tronic automatic. The electric motor in both cases is powered by a 0.8-kWh lithium-ion battery.
Like their closest rival, the recently revealed BMW ActiveHybrid 5, the new E-Class hybrids are capable of traveling on electric power alone for short distances--less than a mile only--and at speeds of less than 35 mph.
Now for the all-important numbers: the 2013 E400 Hybrid also gets a 3.5-liter V-6 that produces 302 horsepower and 273 pound-feet of torque on its own. Combined with the electric motor, the drivetrain is able to carry the luxury sedan from 0-60 mph in 6.7 seconds and onto an electronically limited top speed of 130 mph.
Mercedes claims its E400 Hybrid should return an EPA gas mileage rating of 24/31 mpg city/highway, a slight improvement over the 20/30 mpg city/highway rating the regular E350 model gets.
The E300 Bluetec Hybrid pairs its electric motor with a 2.1-liter four-cylinder turbodiesel engine rated at 201 horsepower and 369 pound-feet of torque. It will accelerate from 0-60 mph in 7.5 seconds and top out at 150 mph. Initial testing on the less conservative European cycle has shown a combined fuel efficiency of up to 56 mpg.
To further boost efficiency, both hybrid sedans also get an engine stop-start system, regenerative brakes, aerodynamic aids, low rolling resistance tires, and a “sailing” mode that can decouple the engine from the transmission at speeds of up to 100 mph in order to allow the car to coast along the highway with minimal frictional losses from the drivetrain.
Look out for both cars at the 2012 Detroit Auto Show next month, press days for which commence on January 9. In the meantime access our dedicated show page for all the latest updates.