Obviously, anyone with the financial wherewithal to purchase a 2010 Mercedes-Benz S400 Hybrid is unlikely to be motivated by the technology's fuel savings. Similarly, if someone wants to make a social statement by driving a "green" vehicle, they will likely want their ride to be instantly recognizable as a hybrid.
So the cost-no-object camp is divided. They can either drop their coin on an all-electric Tesla Roadster or, in spite of their bank balance, go with a lowly Toyota. Which begs the question: Is there something in between? We tested Mercedes' newest hybrid to find out.
Like IMA, this setup is incapable of driving the vehicle on electric power alone. What it can do is provide automatic start-stop capability along with electric assist during acceleration. When the gas pedal is released, the hybrid motor/generator also provides regenerative braking. In fact, Mercedes has implemented some novel ideas to reduce parasitic losses and improve overall efficiency. The S400 has neither a conventional alternator nor a 12V starter battery. Instead, the hybrid motor/generator provides all the electrical power for the vehicle and the S400 is also the first mass-produced hybrid to use a lithium ion battery.