For the 2012 model year, the S-Class family adds a new member--one with better fuel economy than any of the other five models. That brings the lineup to six members in all--two with V-12 engines, two with V-8s, one hybrid model, and one turbodiesel.
The new S-Class mileage leader is the S350 BlueTEC 4MATIC, equipped with a 3.0-liter turbodiesel with 240 horsepower and 455 pound-feet of torque. Even shod with standard all-wheel drive, it's EPA-rated at 21/31 mpg, and doesn't omit any of the usual S-Class standard equipment in the name of cost savings or complexity, as the hybrid does. Performance is competitive with the hybrid--0-60 mph times of about 7.5 seconds are possible--and on the move, the diesel drivetrain's very refined.
The S400 Hybrid, in contrast, offers less in the way of gas mileage than the S350, and a less refined driving experience. EPA-rated at 19/25 mpg, and priced above $92,000 like the diesel, the Hybrid model's moderate acceleration is the end result of combining a lithium-ion battery pack with 20-hp-equivalent electric motors, a 275-hp V-6 gas engine, and a seven-speed automatic. The mild hybrid S400 has an electric-only mode, but only at low speeds, and incorporates stop-start technology, but in real-world driving, just can't match the seamless experience of any other S-Class, nor their performance, nor the diesel's extreme economy and range.
This year's S550 keeps its name, but the engine under the hood is completely new. The old V-8's been replaced by a 4.6-liter, twin-turbo unit that lifts output from 382 horsepower to 429 horsepower. Offered with rear- or all-wheel drive, the S550 puts power to the ground through a seven-speed automatic that helps fuel economy greatly: it's rated at either 15/25 mpg with rear-wheel drive, or 24 mpg highway with the added traction. In our experience, the numbers can be a little shy of reality: we've hammered along a 200-mile interstate run at 80 mph and delivered an indicated 25.5 mpg, while cruising on the S550's effortless wave of passing power, with just a little whistle and grumble indicating the change in engine fundamentals underhood.
For those looking for something not only better-performing, but more exclusive, there's the rear-drive S600, its 510-hp twin-turbo V-12, its 0-60 mph time of 4.5 seconds, and its peaceful whir during any sort of ordinary commuting. The V-12's automatic has manual-shift programming and the engine is so torquey that it hardly needs to be worried with shifting, but its transmission has only five gears instead of seven.
These "mid-range" S-Class models--the diesel, the S550 and S600--are connected cars, with good handling and electronic controls that can filter off the worst offenses the highway can offer up. The S-Class has a very absorbent, well-settled ride that manages to soak up small potholes with little jarring inside the cabin, while remaining remarkably quiet. We would advise, though that the electric power steering in the S550 feels somewhat lifeless compared to the hydraulic-boost system that other versions get. In any case, there's plenty of feedback when you're rounding tight corners at speed, but little 'feel' of the road; the steering's weighting is just a little too artificial. Whether you get the active suspension system or the base air suspension, the S-Class will soak up even the roughest washboard surfaces or potholed city streets without ever feeling floaty.
For those craving a near exotic-car level of performance (and exclusivity), but with practicality that's on par with other S-Class models, there are two blistering AMG models. The S63 AMG installs a new engine this year, a twin-turbo 5.5-liter V-8 worth 536 hp (or 560 hp with a Performance Package), and a 0-60 mph time of 4.4 seconds (or 4.3 seconds). All figures are better than the prior version's 6.2-liter V-8. The S65 AMG, topping $211,000, throttles the turbo V-12 for a stupendous 604 hp, twists out a 4.3-second time from 0-60 mph, and hurtles on to a limited top end of 186 mph. The S63 uses the same seven-speed automatic as the S550, while the S65 gets the five-speed automatic; both adopt AMG's SpeedShift controls, with three shift modes (Comfort, Sport and Manual) for near-total control of power changes. These AMG cars are more different than ever at high speed and on a twisty road because AMG has reworked the electronics for the Active Body Control and employed a torque-vectoring system for quicker turn-in and a more confident corner exit. And the greens have won a victory here, at least on the S63: stop-start technology means up to 23 mpg highway, which means the sedan no longer is subject to the gas-guzzler tax.