E300 Bluetec Hybrid

The 2012 Detroit Auto Show is in full swing, sometimes literally, with musical acts gracing stages and the occasional appearance by, say, Jon Lovitz for the Smart For Us pickup concept. But despite the hoopla, the cars are still the real stars. The two that just crossed Mercedes-Benz's stage are of the green sort, though they're painted brown. Both of the new hybrid E-Class sedans combine a 27-horsepower, 184 pound-feet of torque electric motor with a combustion engine to deliver what Mercedes-Benz claims is the most efficient full-size sedan in the world--at least in the case of the...