Eco-friendly flagship

Luxury driving with a clear conscious is the aim of the new Mercedes-Benz S400 Hybrid

The Mercedes-Benz S-Class may be the top-selling full-size luxury sedan in the world, but even it’s not safe from criticism.
With carbon footprints and eco-sensibility top of mind, a large, rear-wheel drive German flagship may not come across as the greenest way to motor about.
That’s largely why Mercedes has set out “to disprove the theory that sustainable mobility can only be achieved with small cars,” via its new S400 Hybrid. Powered by a V6 gas engine and an electric motor, it averages around 7.9 L/100 km (36 mpg).
The first hybrid production car from Mercedes-Benz, the long wheelbase sedan joins a refreshed 2010 S-Class lineup this fall.
“There is no other vehicle identified more strongly with the Mercedes-Benz brand than the S-Class,” said Ulrich Mellinghoff, the automaker’s VP of development safety, NVH and testing. “It stands for maximum comfort and safety, for luxury, refinement and for status.”
Engineers said the automaker’s polished reputation is part of the reason it’s a tad late to the hybrid vehicle party. Researching alternative propulsion since 1992, Mercedes decided green technology in its machines should be largely invisible to its discerning clientele.
The latter is primarily why M-B designed its gas-electric S-Class as a single-mode hybrid, rather than a dual-mode like it main rival, the Lexus LS 600h L. Note: This means the Benz cannot drive on electric power alone like its Asian counterpart.
Frank Steinacher, product manager for the S-Class, sees this as an advantage. He says the LS must carry extra weight and cuts into its cargo capacity to add the technology necessary for electron-only motoring. Plus: “Its electric drive is small, only for short distances... It’s more marketing than a customer benefit.”
To that end, the S400 Hybrid is the first production hybrid on the planet to use a lithium-ion battery. Versus today’s ubiquitous nickel-metal hydride technology, it stores more volts in a smaller, lighter package. The battery is tucked under the S-Class’ hood instead of in the cargo area like most other gas-electrics, and compared to the model it’s based on, the hybrid’s only 75 kg (165 lbs.) heavier. Mercedes-Benz filed 25 patents in the battery’s design.
The S-Class Hybrid is based on the V6-powered S350, a model not previously offered in Canada. For hybrid duty, M-B modified its 3.5-litre engine for increased efficiency. Alone, it makes 279 horsepower and 258 lb-ft of torque.
Sandwiched between the V6 and the S400 Hybrid’s seven-speed automatic transmission is a 20 hp (15 kW) electric motor – the key ingredient in this German green machine.
As in other hybrids, it has three jobs: Under acceleration, it takes burden off the gas engine by adding power — together they make 295 hp and 284 lb-ft of torque; under braking, it acts as a generator, lassoing kinetic energy to recharge the battery; and, at a stop, when the V6 shuts down, it runs a panoply of systems and re-fires the engine when the S-Class motors out.
In the end, this hybrid system is basically an electric assist. It does the job, though: Mercedes says the S400 betters the Lexus LS’ fuel economy and puts out less CO2.
During our test drive, the seamlessness of the S-Class’ hybrid system impressed. We also drove a V12 S600 that day and the two models largely rode and handled to the same high standard. The S400’s only downfall is somewhat mediocre acceleration and an exhaust note that’s a tad wimpy for a six-figure sedan.
Still, take the badging off and most folks would not know the S400 is a gas-electric eco-mobile. Even the regenerative brakes and electric steering are competent. M-B’s goal of transparent green tech was largely achieved.
Note, that product manager Frank Steinacher said the hybrid system is “very modular,” hinting that it could debut in the new E-Class sedan soon.
Hybrid gear aside, what we have here is a world-class luxury car. Aside from the exterior updates, the 2010 S-Class gets the latest multimedia equipment inside, including the world’s first split-view main screen, which can display a map to the driver and a DVD film to the front seat passenger.
The S-Class offers five interior colours, five types of wood trim and three grades of leather. We could take up pages listing all the equipment and features. If you’re going to a dealer to spec one out, pack a lunch: it could take a while.
New safety highlights include Attention Assist, a drowsiness detector which monitors 70 parameters and actually warning the driver when they need to take a break; Night View Assist which uses infrared to recognizes pedestrians in front of the car; and Speed Limit Assist which ‘reads’ road signs and shows the speed in the main display. Also exclusive to the S-Class is Active Body Control (ABC) with crosswind stability.
An interesting aside: the S400 Hybrid is not the most efficient 2010 S-Class. Amongst the eight powertrains offered globally, the S350 CDI BlueEfficiency turbodiesel model actually averages a slightly better 7.6 L/100 km (37 mpg). It won’t be sold in Canada. On that subject, Mercedes reps said hybrids are, “just one of our answers to sustainable mobility.”
As it did with the intro of it Bluetec diesel models, Mercedes Canada is being “modest” with it initial allotment of S-Class hybrids until it gauges how well-heeled patrons take to the car. It’s now the most affordable model in the lineup at $105,900.