Monday, November 2, 2009

2010 Mercedes Benz S400 Hybrid



Imagine taking a top-of- the-line Mercedes S class sedan and making it into a hybrid, and one that claims a few firsts at that. This is Mercedes' first hybrid, and before you say, "Big deal," hang in there a bit longer, for the S400 is the first production car to use a lithium-ion battery.

That nifty little bit allowed Mercedes to take an existing sedan and make it a "mild" hybrid without the battery intruding into the interior or the trunk by as much as a millimeter. The battery, in fact, fits under the hood, where the more mainstream one would sit in a non-hybrid car. Check out the slide show and look in the upper left when you see the picture of the engine. That is where the battery is and you can see the cover of it in another picture.

That battery works with an electric motor that produces 20 horsepower. It, in turn, works in cahoots with a very smooth, very refined six that is good for 275 horsepower and 258 lb-ft of torque.

Mercedes claims a zero to 60 time of about seven seconds. After two days behind the wheel of the test car, I have to say Mercedes may have been a bit conservative in that stat.

What about gas mileage? A total of 19 to 26 miles per gallon compared to the V8 powered S550 that is EPA rated at 14 to 21 mpg. I achieved 22 miles per gallon in mostly country driving.

And what a delight this car is to drive -- quiet, refined, plush, comfortable, with good power and handling. You will want to drive it to the other coast, starting, oh, tomorrow.

The reason is that once you get past the equipment under the hood, this is the same car as the S550. Only a sign on the rear and one across the lower dash give away the fact that this is a hybrid.

Hit the start button and a ready light shines in the instrument cluster, and you are set to go. When stopped the car is in electric mode, but there will be no disruption in any of the accessories. When you lift your foot from the brake, the engine fires up and you are off. Keep an eye on the tach or you will never know that the engine has started.

In virtual silence, I might quickly add. Even at interstate speeds, you will have no problem communicating with those in back. They will find an abundance of head and legroom and even the sunroof was not too bad on wind noise.
You won't know it's a hybrid

Like other hybrids, while braking the electric motor helps recharge the battery, and you get constant feedback on the battery's strength from a pictogram in the instrument cluster -- or in the screen that also displays the navigation system and audio preferences.

The V6 operates on the Atkinson principle, which delays the closing of each intake valve, increasing thermal efficiency, and reducing fuel consumption and exhaust emissions. The electric motor makes up for the Atkinson's inherent lack of low speed torque and throttle response.

It is worth repeating that one would never know from driving this car that it is a hybrid.

The base price for the S400, which is now at dealers, is $87,950. The S550 starts at $91,600.

source: marketwatch