Mercedes does hybrid right with S400

Forget every perception you've ever had about those funny-looking albeit economical hybrids. Their look often made a statement for those wanting to make a statement.

Then hybrids went more mainstream, showing up in economy cars, midsize sedans, SUVs and even the pickup segment. Introducing the top-line luxury in a hybrid: the 2010 Mercedes-Benz S400.

Europeans, generally, never paid much attention to hybrids. Diesel is king over there – around half of new cars sold are diesels. Thirty percent better fuel economy, and cleaner burning, they'll tell you. But Mercedes finally has plunged into the hybrid fray, joining BMW and Lexus.

Mercedes spokesman Gregory O'Shea came by not long ago to give me a glimpse of this hybrid beauty – and boast that the S400 offered the first lithium-ion battery made for cars.

The battery pack only is about the size of a six-pack so, rather than stash them under the rear seat or somewhere that compromises passenger or cargo space, it fits neatly into the engine compartment – right where the 12-volt battery usually rides.

To make room, the 12-volt battery is in the trunk. The 60-pound lithium-ion pack sits in its own housing and has its own cooling circuit. The disc-shaped electric motor is situated between the engine and transmission.

The S400 actually has a simpler hybrid system than some others. The S400 is equipped with a 3.5-liter V-6 that puts out 275 horses and 258 pound-feet of torque. That's complemented by a magneto-electric motor that's worth about 20 horses, but it has great low-end torque to give the car an extra jolt off the line.

Combined, they can power this hefty piece of luxury to 60 mph in just over 7 seconds. Now that's not bad, considering comparable V-6s from Mercedes are doing about the same.
But more important is the mileage: It averages around 20 in the city, 30 on the highway. And that admirably compares to the 14 city, 22 highway in the Mercedes S550 – the S400's closest relative.

Now, to contradict myself about this simple system, know that this hybrid is controlled by a computer that recalculates the best operating mode a mindboggling 160 times a second.
The engine shuts down when the S400 comes to a halt. But not to worry: When stopped at a traffic light, the electric motor operates the air-conditioning and power steering.

On the road, this beauty handles elegantly and confidently. Mercedes' all-wheel-drive system, however, is not available with the S400.

Regulating speed is a 7-speed automatic, which is decisive and smooth.

Bottom line with this hybrid: You'll hardly know it is one. It drives smoothly, and the engine and motor work together seamlessly.

Of course, you will be reminded of its hybridity by the display inside that shows the ratio of power, charging of the batteries and the car's current fuel economy. It's also differentiated by seven-spoke, 18-inch wheels and hybrid logos on the trunk lid and dash – and badging on the fenders, too.

Equally impressive is the quality of materials inside, starting with an upgraded wood and leather steering wheel. At night, ambient lighting illuminates the interior in one of three colors: white, amber and ice blue.

As with all S-class models, comfort is king. Soft, leather seating offers elegance and comfort. Head, shoulder and leg room are more than adequate.

Mercedes gave a big boost to safety in the S-Class this year. Steering sensors identify your driving style in the early goings, then can identify when you're making additional steering corrections and will inquire, "Time for a rest?'

The driver also is alerted with steering-wheel vibration if the car drifts into the next lane. A night-view assist feature on the instrument cluster helps make pedestrians far ahead more visible.

Fortunately, I didn't get to test this feature: The optional Distronic Plus, Mercedes' Pre-Safe system, will sound three warning tones and then apply partial or even full braking moments before an impending crash. The distronic system also warns of blind-spot vehicles with a beep.

And another new system, in the event of a strong highway crosswind, actually will adjust wheel struts to change wheel load to help keep the car on the road.

So if you're looking to save some money at the gas pump, the S400 is a sure bet. But Mercedes guy O'Shea says the savings go beyond the fuel savings.

First, the purchase price actually is $4,000 or so less than the comparable S550. Yes, instead of paying a premium for the hybrid, it's less. Second, there's currently a tax credit for hybrids of $1,195. Third, no gas-guzzler tax.

If horsepower is your thing, consider the S550. If you seek luxury with the hybrid mileage, you might check out the BMW hybrids in the X6 and Lexus' LS600h, too. But be warned that the S400, with all savings, safety and luxury, is a tough cookie to top.

The 2010 Mercedes-Benz S400

Price: $88,000

As tested: $93,775 (with premium package of adaptive headlamps, seats with massage feature, parking guidance and rear-view camera)