First Drive: Mercedes Benz S400 Hybrid

The Mercedes Benz S400 Hybrid is the world’s first mass produced car with a lithium ion battery. It’s the first Mercedes with a hybrid drive. And, with a price tag likely to approach or exceed $100,000, it’s going to be an ultra-niche vehicle. The S400 Hybrid will arrive in US showrooms beginning in August 2009.

Its competition in the nascent luxury green vehicle market will be the $109,000 two-seat all-electric Tesla Roadster; the $87,000 four-door Fisker Karma plug-in hybrid (not yet out); and the $104,000 Lexus LS 600h L—a V8 hybrid averaging 21 miles to the gallon. Lexus annually sells about 1,000 units of the LS 600h L.

Mercedes S400 Hybrid
Mercedes S400 Hybrid

We achieved 29.3 miles per gallon in the Mercedes S400 Hybrid, over a 150-mile mixed driving course though Southern Germany.

Benz estimates fuel economy for the S400 will be 23 in the city and 33 on the highway. EPA numbers are not yet official, but HybridCars.com did our own mileage test of this big luxury sedan on the roads of Southern Germany. Our drive loop took us from Stuttgart—the home of Mercedes Benz—to the town of Buel and back, a round trip of approximately 150 miles. The route was evenly comprised of high-speed driving on the Autobahn—where we ran at, ahem, greater than 100 mph—as well as moderately paced rural roads, and narrow streets through smaller hamlets. We achieved an impressive 29.3 miles per gallon—not bad for a car that weighs almost 5,000 pounds. (By the way, the V6 of the S400 is plenty strong for the Autobahn.)

With much stricter speed limits in the US, it’s reasonable that fuel economy results will be even better. But saving fuel and money is not the first concern for buyers of this car. The buyer of the S400 hybrid is probably just as interested in pairing the Mercedes three-pointed star emblem with a hybrid badge, to demonstrate a combined interest in luxury, refinement, and green status. Mercedes claims that the S400 is the “CO2 champion in the luxury class,” emitting a relatively low 186 grams of carbon per kilometer.

As the hybrid version of the Benz flagship S-Class sedan, the S400 is powered by a mild hybrid system with a 3.5-liter V6 gas engine. The hybrid system allows Mercedes to maintain its high-power profile, while using a V6 instead of a V8 or V12. The electric-gas combo provides a total output of 295 horsepower, channeled through a seven-speed automatic transmission. Benz is particularly proud of what it refers to as “compact” batter technology. Engineers made this hybrid system as well-packaged and light as possible. (Mercedes-Benz was able to fit the entire pack into the same space, at the right-hand base of the windshield, that previously housed the car’s standard lead-acid 12-Volt starter battery.) The S400 weighs only about 120 pounds more than the standard S-Class.

Driving Manners

The S400 drives much smaller than it is. Cutting through the tight twisties of Germany’s Black Forest, this hybrid cornered flatly and with confidence. It is as nimble and agile as its gas-powered counterpart. Stability comes from Active Body Control, an active suspension that continually adapts the suspension tuning to the current driving situation. The S400 features Torque Vectoring Brake, as well as Crosswind Stabilization, both enhancing the sure-footedness of the car. Other high-tech advancements include a pre-collision system, adaptive high beam assist, lane keep assist, and radar-based cruise control.

The cabin of the car is as plush as the standard S-Class. It shares all the same luxury features including a new split-view driver interface, which allows the front passenger to watch a movie without distracting the driver. There’s also a “Night View Assist” feature that detects pedestrians on the road ahead. The only interior difference is the S400’s hybrid gauge showing the flow of power between engine, battery, and regenerative braking.

The S400 shares the look of the S-Class. Signs of its recent facelift include a more aero grille, revised LED lighting at the front and back, and new mirrors, tailpipes, and wheels.
The Mercedes Benz S400 hybrid is a luxurious, fuel-efficient saloon with lots of driving appeal. With its steep purchase price, it’s obviously not for everyone—but it is one more option for uncompromising affluent buyers seeking a slightly greener ride.


  • BMW Fan

    Reality check folks.

    A BMW 335d achieves better mileage than this with a lot more pep (I’m betting that even with an electric motor this Mercedes is not going to post 425 ft/lbs of torque.) And you could buy two 335d’s for the price of just one of these Mercedes.

    This car theoretically competes with the high-end Lexus hybrid LS 600h L, but these hybrid ubersedans really seem to be niche vehicles that practially border on prototypes. I wonder how many Mercedes will sell in a month? Nineteen Lexus LS 600h Ls sold last month, so if Mercedes takes half the market they may sell 9 or 10 per month. This brings me back to my initial statement:

    Get real folks.

  • Electric Guy

    The real competition for this car will be the Telsa Model T. For those who can spend $60 to $100+ for a luxury vehicle, Telsa full electric, 300-mile per charge will be the car to beat. Mercedes might as well just stuck a ‘Hybrid’ sticker on the current car and added another battery in the engine compartment. This is the same mistake that GM made trying to sell giant SUVs with a ‘mild hybrid’ concept, getting less than 30-mpg.

  • Detroit Guy

    29.3 mpg isn’t impressive. You don’t need a Lithium Ion battery for that. My Ford Fusion gets that and looks better doin’ it. Save your money and grab a Chevy Volt. It sounds like we’ll be able to save a lot of gas money with it.

  • cferger

    I’ll take the fisker thank you very much.

  • Detroit Guy

    …and I’ll save the money.

  • Stephen Trask

    The “save your money and buy a Chevy” argument is not one that usually resonates with the average Mercedes buyer. The importance of this vehicle is in it’s technical breakthroughs, like the battery, which can be amortized across vehicle sales because of the particular niche for the car, and then trickled down to less expensive cars. Imagine what 70-100 less horsepower and 1000 fewer pounds would do for mileage. Given the type of company that Mercedes is, this seems like the most sensible approach to getting this particular technology on the road. Now if Ford came out with a $100,000 hybrid as their first attempt it would be silly. But for Mercedes to start with it’s flagship sedan makes total sense.

  • Gap Spanner

    It always amazes me that any advancement that does not cost pennies and is not immediately available to the mass market is denigrated. I remember when electric calculators first came out – four mathematical functions, no memory, terrible battery life and awful red glowing LED displays. And they cost a fortune. They were considered nothing more than expensive, useless toys. A $5 watch does more now. Same with cell phones – once a sign of ostentatiousness and arrogance, they are so ubiquitous as to be invisible (except to law enforcement types following you in traffic). So let the ultra rich people buy the high-end luxury vehicles – and let them provide the funding for further research so that, within a few more years, this technology will be available to the average consumer.

  • fred smilek

    Wuaaauuu this car is amazing…

  • Gun Runner

    Gap Spanner makes a very valid point.

  • aferda

    Completely agree with Gap Spanner. Just because I cannot afford this vehicle, that does not mean that it is not a critically important breakthrough. Keep in mind that the S-Class has pioneered many new technologies which are now found in many less expensive cars including the ABS anti-lock braking system, which made its debut in the S-Class in 1978. In 1981, airbags and belt tensioners were offered for the first time followed by the first electronic stability program, traction control, and automatic air suspension (airmatic). That Mercedes can get these results with a battery pack the size of a normal automotive batter is astounding.

    I grant you that the Ford is better for the environment but realistically the buyers will not cross shop them.

    Consider this: Each S-class hybrid will reduce fuel consumption in a 50/50 mix to 28 mpg from 18 mpg for the gas model. The Ford Fusion Hybrid, by comparison, reduces consumption to 38 mpg from 27 mpg. That means that each Mercedes buyer that chooses the Hybrid model will save twice!!! the fuel (1.98 gallons) per 100 miles driven that a Fusion buyer will by selecting the hybrid model (1.07 gallons). MPG unfortunately masks this, which is why gallons per 100 miles would be a much better way to measure consumption.

  • Need2Change

    The 335d and S400 are not comparable cars.

    The BMW 335d is 178″ long, and 71.5″ wide with a small trunk.
    It is only 3″ longer than a U.S. Ford Focus.

    The S400 is 22″ longer and 2″ wider than the BMW, and has a 20 cubic ft. trunk.

    The S400 should be compared with the 7-series, and not the 3-series.

    The BMW 750 Li gets 14 mpg city, is subject to gas guzzler tax, and has a base cost of $85K, but can sticker for $100K with options and guzzler tax. It is much faster than the S400.

  • Turkish Fanbelt

    Don’t knock it too much. The S400 is greener and more efficient then any of the two-mode hybrid SUVs and trucks.

  • RKRB

    If you buy a Mercedes, the economy or greenery are minor considerations, so who cares what kind of mileage it gets, or whether it can beat a BMW? Any big Mercedes just seems to say, “Hey, everybody, look at me, I’ve got mine. Let somebody else drive economy cars.”

    Engineered like no other, you betcha. As a former Mercedes diesel owner, I found regular and unscheduled maintenance costs resembled a new car payment, and would recommend avoiding these barges unless you have a warranty. It’s a mystery how Mercedes can avoid the oversized/gas-guzzler/envirocidal/lemon-y image of GM (or even Hummer). Well, diversity is strength, but I’ve done my time. You can call it quality or engineering or whatever you want, but it seems that Consumerist Greed, Thy Name Is Mercedes-Benz.

  • Itman
  • reality bites

    ‘BMW Fan’ really should get automotive help.

    There is no competition between the cramped and poorly built 335 compact saloon and the grand luxury and technical tour de force that is the latest MB S-Classe. You really are saying something very silly indeed.

    If you weren’t wearing your colors so clearly as a ‘BMW Fan’ then the blindness of your comment would be unforgivable.

    Check out the green credentials of the S-Classe; it is one of only three cars in the world to achieve TuV approval for it’s build and recycling credentials. And guess what? The other two are not BMWs.

    The day BMW makes a car anywhere near as good as the S-Classe is the day i will shove a nest of wasps up my 4ss.

    MB was the first manufacturer in the world to produce a car that had ABS, power windows and ESP. Oh, and they also built the first diesel car. In fact, MB actually invented and built the first car in the world – how about that? What has BMW invented? The user un-friendly iDrive. And the X6. Come on… WTF is that thing?? Whatever next, a 5-series hatchback that hopes to copy the success of the CLS-Classe but was designed by a sneezing 5 year old child drawing with a blunt cucumber dipped in mud as a pen?

    There is, and never will be, any sort of comparison between a 3-Series and an S-Classe in this country, on this planet, in this universe or in any parallel time dimension you care to invent.

    Oh… can I smell coffee?? It may be wafting your way right this very moment.

  • Mercedes Fan

    It’s probably going to be hard to find spare parts in case you get in a crash, but generally rich people buy these cars anyway. It’s great Mercedes is trying something new; 29.3 mph is exceptional.

  • Anonymous

    A BMW is twice as small as Mercedes S and a

  • mercedes fan

    1 of every 5 S-classes sold in the world after the facelift is S400 HYBRID. And the S-class is better than the BMW and the Lexus. I still haven’t seen LS600h here in Europe in the real world and i’ve seen a lot of S350 CDI and S400 HYBRID

  • tim9

    Although I can only afford to drive a used MB,,,,I can say for a fact,,,MB is a fantastic vehicle. I spent 25 years working and repairing autos,,,Ford and GM dealerships and then 16 years with my own shop. BMW is a great driving car,,,,but they are no way the same quality as a MB.
    Today I drive a 20 year old MB 300TDT. Granted,,,it’s a 20 year old vehicle,,,but that 300 TDT gets over 28 MPG,,,and weighs in at over 6000 lbs. I’m sure people were saying the same about it 20 years ago. Maybe in 15 years,,,I’ll get me one of these used S400 Hybrid. I bet they will still be on the road,,,because MB builds cars that last,,,

  • althebutcher

    You may want to check your facts as mercedes was not the first with either abs or air bags.