When it comes to large luxury sedans, few convey as much grandeur and success as the 2008 Mercedes-Benz S-Class. For decades, the Mercedes flagship has been the quintessential premium sedan for well-to-do doctors, lawyers, high-ranking executives and foreign oil magnates who seek the finest automobile money can buy -- without seeking out models from Bentley, Maybach or Rolls-Royce. Now in its second year since a complete redesign, the four S-Class varieties are still at the top of a very prestigious mountain of high-end sedans.

If the 2008 Mercedes-Benz S-Class could be summed up in three words, they would be power, elegance and technology. The power bit is taken care of in good order by four engines, each of which motivates this supremely hefty Benz as if it weighed hundreds of pounds less. At the bottom of the totem pole is the S550's 5.5-liter V8 that delivers 382 horsepower through a seven-speed automatic transmission to either the rear wheels or all four in the 4Matic model. The S63 AMG, developed by Mercedes' in-house tuning division, features a naturally aspirated 518-hp V8. The V12-powered S600 features twin turbochargers that produce 510 hp and 604 pound-feet of torque. If that seems slow to you, you may need a psychiatrist, but otherwise, the S65 AMG and its biturbo V12 makes 604 hp and an NHRA-challenging 738 lb-ft.

The elegance part is taken care of by tasteful styling that is particularly striking with the AMG body modifications on the S63 and S65. Inside, Mercedes' new COMAND system creates a classy and uncluttered cabin free of the zillions of buttons typical of many luxury cars. Rich leather covers most surfaces, while real wood trim is tastefully applied in an orbit around the cabin, with soothing lights hidden beneath. Finally, technology like a 20GB hard drive-based navigation system, adaptive seats, Active Body Control suspension technology and Distronic Plus cruise control offer an impressive range of capabilities that set the S-Class apart from the pack.

Depending on which of the five models is in consideration, S-Class competitors range from the Audi A8 and BMW 750i to the Bentley Continental Flying Spur. Against any of them, though, the 2008 S550, S550 4Matic, S600, S63 AMG and S65 AMG provide a brilliant mix of elements that is tough to match: abundant power, competent handling, high-tech features, an opulent interior and magnificent presence. Those foreign oil magnates won't be disappointed.

There are currently five trim levels available on the flagship 2008 Mercedes-Benz S-Class luxury sedan: the S550, the all-wheel-drive S550 4Matic, the V12-powered S600, the high-performance S63 AMG and the über-performance S65 AMG. Notable items on the S550's standard equipment list include 18-inch wheels, an air spring suspension, bi-xenon headlights, 14-way adjustable front seats, the COMAND all-in-one control interface, a hard-drive-based navigation system, hands-free cell phone communication, a Harman Kardon audio system with a six-CD changer and, of course, copious amounts of leather and wood trim. With the exception of its AWD system and some accompanying chassis modifications, the S550 4Matic is identically equipped. In addition to a larger, more powerful V8 engine, the S63 AMG adds 20-inch lightweight AMG wheels, Mercedes' Active Body Control (ABC) adaptive suspension (optional on the rear-drive S550), larger brakes, specific exterior styling pieces, aluminum interior trim and sport seats.

Major options on the V8-equipped S-Class cars include ventilated front seats with a massage feature, a keyless entry and start system, the Distronic Plus adaptive cruise control and Night View Assist infrared night vision system. One can also order an AMG wheel-and-body trim package for the S550, while a performance package for the S63 provides a limited-slip rear differential and raises the top-speed limiter from 155 mph to 186. The Rear Seat Package equips either model with power-adjustable heated and cooled rear seats and four-zone climate control.

The V12-equipped S600 and S65 AMG sedans come with almost all of the above features as standard. Although vastly more powerful, the S65 basically takes the same approach to performance as the S63 and features the same upgraded running gear and cosmetic additions.

The 2008 Mercedes-Benz S550 sports a 5.5-liter V8 that makes 382 hp and 391 lb-ft of torque. In testing, we've found that this is enough for a 6.1-second 0-60-mph time. A standard seven-speed automatic transmission routes power to the rear wheels. Opt for the S550 4Matic and this same transmission routes power to all four wheels, transforming the big luxury sedan into a serious bad-weather vehicle. The Mercedes S63 AMG has a 6.2-liter V8 capable of 518 hp and 465 lb-ft of torque. The S63 also uses the seven-speed automatic, but it's recalibrated for faster, firmer shifts.

A choice of two 12-cylinder engines is found in the two remaining S-Class models. The S600's twin-turbo V12 is of the same displacement as the V8, but provides 510 hp and 612 lb-ft of torque. For the S65 AMG, a twin-turbo 6.0-liter V12 develops a positively insane 604 hp and 738 lb-ft of torque. Anything more would have to be fueled by nuclear fission. Mercedes says the S65 AMG can hit 60 mph in 4.2 seconds. On the V12s, Mercedes sticks with a five-speed automatic since the seven-speed unit isn't capable of handling the V12's torque output. The S65 has a sport-tuned version of this automatic that provides quicker shifts.

It may be a stretch to compare the 2008 Mercedes-Benz S-Class to a tank, but with its state-of-the-art safety systems, it's one of the closest things to one. Stability control, eight airbags (including full-length curtains and side rear airbags) and brake assist (which automatically applies full power braking if it senses a panic-stop situation) are all onboard. So is Mercedes' PreSafe system, a useful bit of technology that can sense an impending crash and automatically tighten up the seatbelts and reposition the power seats for maximum airbag protection. Active headlights are also standard, while Night Vision Assist uses infrared technology to detect objects far beyond headlight range.

The S-Class suspension utilizes Mercedes' Airmatic suspension system wherein four air bellows support the weight of the vehicle. Under lateral weight transfer during cornering, the outside bellows inflate to reduce body lean by as much as 40 percent. Ride and handling capabilities are exactly what you'd expect from a high-end sedan -- yet also what you wouldn't. The ride is compliant and fitting for a luxury sedan, dispatching bumps and ruts with nary a shake to the cabin, while the tight handling makes the S550 feel two-thirds its size. "Nimble" may be too strong a descriptor, but considering the 2008 Mercedes-Benz S-Class weighs a minimum of 4,300 pounds, it feels surprisingly agile. The steering is fairly quick and precise with a decent heft to the wheel, though we'd still give the BMW 7 Series a slight edge in road feel.

Mercedes' COMAND (Cockpit Management and Data) system is much easier to use than before, as there is a larger screen mounted to the right of the instruments and many controls are redundant. The only ergonomic flaw is the turn signal stalk, which is located somewhat awkwardly down low and away from the driver. Simple elegance marks the cabin decor, with impeccable materials quality, richly polished woods and soft leather all around.

The optional dynamic multicontour seats have 11 air chambers that essentially allow you to mold the seat to your body. During aggressive driving, the side bolsters can automatically pump up and down in response to cornering forces to better hold you in place. These seats can also provide a soothing back massage, which will no doubt decrease business for in-car masseurs. Those in the rear seat will also be well taken care of, particularly when the S-Class is equipped with the Rear Seat package that adds power adjustment, heating and cooled seats, and its own set of two-zone automatic climate controls. The only thing missing is a butler named Cavendish.