There are six different engines and a total of seven different powertrain combinations in the 2013 Mercedes-Benz S Class--two with V-12 engines, two with V-8s, one hybrid model, and one turbodiesel. And S 550 models come with a choice of rear-wheel drive or 4Matic all-wheel drive, while 4Matic is mandatory with the diesel.
While the S 550 models aren't the most fuel-efficient or affordable, they're bound to be the most popular models in the S Class lineup. Last year they were replaced by a new 429-horsepower, 4.6-liter, twin-turbo V-8, and 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. We've found this powertrain to be a real-world joy, with even better fuel economy, plenty of power on reserve, and just a little turbo whistle.
Those seeking greener pastures will want to go with either the BlueTec diesel or the S 400 Hybrid. The S Class mileage leader is the S 350 BlueTEC 4MATIC, equipped with a 3.0-liter turbodiesel with 240 horsepower and 455 pound-feet of torque. It's EPA-rated at 21/31 mpg yet includes all of the features and complexity you'll find in the rest of the S-Class lineup. 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.
On the other hand, the S 400 Hybrid is EPA-rated at 19/25 mpg, with respectable acceleration from the union of a lithium-ion battery pack with 20-hp-equivalent electric motors, a 275-hp V-6 gas engine, and a seven-speed automatic. At low speeds it can run on electric power alone, and it uses stop-start technology; but we've found that this powertrain simply isn't quite as smooth and seamless as other luxury hybrids or as the other S Class choices.
The better-performing rear-drive S600 is the pick for those wanting something more exclusive. 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.
Top spots in the S Class lineup are held by the AMG models, which offer an exotic-car level of performance (and exclusivity), but with practicality that's on par with other S Class models. With 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), the S 63 AMG is probably the top pick for those craving performance. But for even more, there's the S65 AMG, which throttles the turbo V-12 to a stupendous 604 hp, twisting out a 4.3-second time from 0-60 mph, and hurtling on to a limited top end of 186 mph. The S 63 uses an AMG SpeedShift version of the seven-speed automatic, while the S65 gets the five-speed automatic. You also get 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 S 63: stop-start technology means up to 23 mpg highway, which means the sedan no longer is subject to the gas-guzzler tax.
Both of the mid-range cars, 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. Steering feel and weighting tends to be a little disappointing in the S550, which has electric power steering, however.