The one absolutely unassailable benefit about the hybrid revolution is that it has upset the homogeneity that has been pervading the automotive industry as of late. Take the uber-luxury sedan segment. In recent years, almost every manufacturer - BMW, Audi, Jaguar and Mercedes-Benz - followed the same strict formula: A mid-displacement V8 powered the entry-level model - if an $85,000-plus sedan can ever be called entry-level - upstaged by a seriously expensive 12-cylinder land yacht. It was a protocol that the BMW 7 Series, Mercedes-Benz S-Class, Jaguar XJ and Audi A8 followed without variation. That's until the green revolution and the Lexus LS 600hL threw a monkey wrench into the entire regimen.
Suddenly, the strict eight- and 12-cylinder protocol was no longer universal since the LS hybrid stood atop the Lexus lineup where a V12 normally stood.
It's been a couple of years since the LS 600 made its debut and we finally have Europe's answer with both Mercedes and BMW offering hybrid versions of their iconic S-Class and 7 Series luxo-barges.
But this is where that divergence I mentioned comes in. Where the LS 600hL stresses fuel economy with adequate performance and the BMW ActiveHybrid 7 - in keeping with corporate philosophy - is all about performance with its hybrid electric motor hooked up to a twin-turbo V8, Mercedes takes the opposite tack, marrying its small 3.5-litre V6 with a "mild" hybrid powertrain to emphasize economy, both in sticker price and fuel consumption.
The S400 is really the economy-minded - again, if anything that retails for $105,900 can be called economical - luxury hybrid, the technology a far cry from the complicated arrangement the LS 600 and even Toyota's much lower-cost Prius boast. Instead, the Mercedes uses a very Honda Insight-like arrangement with its 20-horsepower electric motor sandwiched between the V6 engine and the transmission. Besides, though the Mercedes is the first production automobile to use the much-touted lithium ion battery for hybrid use, it's a tiny affair, not much bigger than a standard automotive battery and much smaller than those powering full hybrids.
All this means that the electric motor cannot power the big Merc all by itself. It does allow the engine to shut off at stoplights, however, and acts in concert with the V6 when serious acceleration is called for. It is, in these two ways, that the hybrid conserves gas compared with the V8s and V12s otherwise employed in Mercedes' top-of-the-line vehicles. Rated at 11 litres per 100 kilometres in the city and 7.7 L/100 km on the highway by Transport Canada, the S400 is, on paper at least, more frugal than Mercedes' smallest V8, the S450.
And it delivers on that promise of superior fuel economy, though it depends on the type and style of driving you do. Driven Prius-like frugally on the highway, for instance, can see the S400 sip as little as 8.7L per 100 klicks, superior mileage for a monster as large as the S-Class. Driven in a more Boothian manner around town, the average was in the 12.5-L/100-km range, still better than what I usually achieve in most large luxury sedans but certainly not otherworldly.
But even if the S400 doesn't always deliver astounding economy, neither does it sacrifice significant performance for the frugality it does deliver. Rated together, the 3.5L/electric motor combination boasts 295 horsepower and 284 pound-feet of peak torque (118 lb-ft alone from the electric motor at truly low rpm). Pushed hard, of course, you'll notice a difference between the S400's thrust and the S550, but on no occasion did the hybrid Mercedes feel anything less than stellar.
My only powertrain complaint is that when goosed hard, the gasoline engine is not the most sophisticated-sounding engine on the planet. It's an unusual 90-degree V6 and, though Mercedes has quelled all the vibration endemic to this odd layout, the engine's exhaust note is not as melodious as one expects from a top-of-the-line Mercedes. The good news is that, with all the low-end torque afforded by the supplementary electric motor, you don't call on maximum warp all that often.
Mercedes' big S-Class has been moderately updated this year with minor exterior and interior upgrades. Nonetheless, it still remains the luxury segment's stalwart, possessed of great luxury along with a plethora of class-leading creature comforts and electronic features. The optional (as part of the Premium package) multi-contour seats are a prime example. Adjusted through the Comand onboard computer, there's a truly dizzying array of padding alterations available not to mention the multi-faceted massage machine (I preferred the fast and vigorous setting; most, however, chose the slow and gentle position. And, yes, slow and vigorous and fast and gentle are options).
Another useful part of the S400's $6,100 Premium package was the rear-view camera, which, combined with Mercedes tilt-down-when-in-reverse side mirrors, is the best combination for easy parking. Lexus may boast automatic parking, but give me the pairing of easily accessible information as to how far my bumper is from creaming the Toyota behind me and exactly how far those expensive alloy wheels are from the curb and I'm a happy camper.
In the end, Mercedes' choice of emphasizing economy over performance in its top-of-the-range sedan is fitting. Unlike those shopping BMW's 7 Series who may be looking for ultimate performance in a large luxury sedan, few buy an S-Class to tear up the road. Besides, there's all manner of options for that kind of behaviour - the S550, S63 and S65. With the S400, driving like a banker doesn't necessarily mean consuming like one.
The Specs:
Type of vehicle: Rear-wheel-drive, luxury sedan
Engine: Electric motor/3.5L DOHC V6
Power: 295 hp @ 6,000 rpm; 284 lb-ft of torque @ 2,400 rpm
Transmission: Seven-speed manumatic
Brakes: Four-wheel disc with ABS
Tires: P235/60R17
Price: base/as tested: $105,900/$114,500
Destination charge: $1,995
Transport Canada fuel economy L/100 km: 11 city, 7.7 hwy.
Standard features: Power door locks, windows and mirrors, front and rear air conditioning with micron air filter, harman/kardon AM/FM/CD/MP3 player, Sirius satellite radio, steering wheel-mounted audio controls, navigation system, cruise control, power glass sunroof, information display, tilt and telescopic steering wheel, leather seats, 12-way power adjustable front seats, heated front seats, auto headlights, power rear sunshade, dual front air bags, side curtain air bags, Attention Assist, Adaptive Highbeam Assist, TeleAid emergency calling system, Advanced Parking Guidance.
