2010 Mercedes-Benz S400 Hybrid Review: Full Size Luxury
|Topics: Mercedes-Benz S400
James Flammang, autoMedia.com
7 December 2009
Mercedes-Benz has been busy with BlueTec engines over the past few years, taking the diesel route toward improved fuel economy. Until the 2010 model year, though, hybrid-powertrain models have been absent from the German automaker's lineup.
The new S400 Hybrid isn't the first full-size luxury sedan to adopt gasoline/electric operation. Lexus launched its LS 600h L sedan, with a comparable hybrid powertrain, as a 2008 model. Both companies evidently believe there's a significant urge for greater fuel economy and reduced emissions, even at the upper end of the economic scale.
One big difference lies in the battery. With the S400, Mercedes-Benz is the first automaker to issue a series-production model with a lithium-ion battery pack that fits into the engine compartment. Except for seldom-seen Fisker and Tesla cars, other hybrids use nickel metal hydride batteries.
Under the S400 hood, a 3.5-liter V-6 gasoline engine generates 275 horsepower and 258 pound-feet of torque. A 15-kilowatt electric motor sits between the gas engine and the seven-speed adaptive automatic transmission, which incorporates Sport and Comfort modes. The electric motor adds 20 horsepower, for a total of 295; plus 118 pound-feet of starting torque, to boost acceleration when taking off.
Unlike some hybrid-powertrain vehicles on the market, this one does not have a full hybrid system. The engine shuts off automatically as you slow down and come to a halt at a stoplight or stop sign, but the S400 Hybrid cannot run on battery power alone. Electricity augments the gasoline engine, but cannot replace its function. In some hybrid models, the gasoline engine shuts off and restarts with a bit of a bump. Not here. It's nearly impossible to discern the transition between engine shut-off and subsequent start-up at a stoplight.
The rear-wheel-drive S400 Hybrid gets a fuel-economy estimate from the Environmental Protection Agency (EPA) of 19 mpg in city driving and 26 mpg on the highway—comparable to a smaller gas-engine car. In contrast, the Mercedes-Benz S550 sedan with a 382-horsepower V-8 gets a mileage estimate of only 15 mpg city/23 mpg highway. Naturally, the S600 with its 510-hp V-12 engine is even less thrifty. Built on a 124.6-inch wheelbase and measuring 206.5 inches long overall, the S400 Hybrid is a substantial automobile, weighing at least 4,390 pounds. That's a lot for any powertrain to push.
Everything is super-smooth in the S400 Hybrid, just as it is in every S-Class sedan. After all, this is Mercedes-Benz's prime model: the very top of the sedan lineup in terms of luxury and comfort/convenience. So, you get nearly every S-Class benefit and element of elegance, coupled with the promise of consuming less fuel and yielding fewer emissions.
With a 0-60 mph acceleration time of 7.2 seconds, performance admittedly falls short of the capabilities of the S550 sedan. Even so, the S400 Hybrid comes close enough to satisfy most potential buyers in this league. Only the most ardent high-end hot rodder is likely to complain about any shortage of screaming acceleration. And those folks aren't likely to lean toward a hybrid of any class, much less the upper-luxury S-Class. Even an S550 or S600 doesn't satisfy everyone, which is why Mercedes-Benz's AMG division turns out super-performance S63 and S65 editions.
Every S-Class model, including the S400, is loaded with technology and driver conveniences. The standard Pre-Safe system can sense an impending collision and tighten seatbelts, as well as apply additional braking force. Mercedes-Benz also offers a Driver Assistance Package that includes a Blind-Spot Alert, Lane-Departure Warning, and Distronic Plus adaptive cruise control. New Attention Assist is a driver-fatigue alert system that provides both an audible and visual warning when it senses lack of alertness.
Back-seat video entertainment with dual screens is available. A Rear Seating Package includes four-zone automatic climate control, a rear-seat memory, and heated/active-ventilated rear seats. A Sport Package includes several appearance items, and may be augmented by a panoramic moonroof. Night View Assist Plus is another extra-cost option, but 20-inch tires are a no-charge alternative to the standard 18-inch rubber. Although the S400 Hybrid is the lowest-priced S-Class model, it's hardly a giveaway at $88,825 (including destination charge). Still, the gasoline-engine S550 sedan stickers for $93,475.
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