When an eight-cylinder luxury sedan simply won't do, a V-12 is the only way to go. And until the arrival of new twelves from Audi, Volkswagen, Maybach, and Rolls-Royce, serious status seekers will have to be content with the all-new BMW 760Li and the newly turbo-charged Mercedes-Benz S600, two cars that are more disparate in character and performance than their cylinder counts would suggest.
BMW's 760Li replaces the 750iL, which was the bestselling twelve-cylinder sedan of its era. Although the displacement of the 60-degree V-12 has increased slightly, from 5.4 liters to 6.0, its output jumped significantly, from 326 horsepower to 438. This is still a normally aspirated engine, but it now features direct fuel injection, four valves per cylinder instead of two, variable intake- and exhaust-valve timing, and BMW's new Valvetronic variable valve lift system. Paired with a six-speed manu-matic transmission, the lightweight V-12 will propel the not-so-lightweight (4872 pounds) 760Li from 0 to 60 mph in 5.4 seconds and on to an electronically governed top speed of 149 mph.
This new powerplant seems completely free of vibration, almost as if there were no reciprocating parts under the hood, and the noise level would be close to zero were it not for some tire boom and suspension thump. Apart from its considerable thirst, the new direct-injection engine can be criticized only for its relative lack of low-end torque: The 444-pound-feet peak is achieved at a relatively high 3950 rpm.
Despite its considerable muscle, the big BMW is handily outperformed by this year's freshly pumped-up S600, which packs a twin-turbocharged, 5.5-liter V-12. The 4610-pound Mercedes will hurtle from 0 to 60 mph in 4.6 seconds and maintains this unrestrained urge way past the 120-mph mark, thanks to perfectly spaced ratios in the five-speed manu-matic transmission and a whopping 590 pound-feet of torque, which peaks at a mere 1800 rpm. The car tops out at a chip-limited 155 mph.
These two flagships seem to accomplish the impossible. They provide almost seventeen feet of splendid isolation as they waft you down the road in silence, style, and splendor, but they also will play along when you decide to switch off their stability control systems and be a hooligan. Surprisingly, the Benz is every bit as good a driver's car as the BMW. Its chassis, equipped with the Active Body Control system, is much tauter and less ambiguous than lesser S-class models equipped with the more indifferent Airmatic setup. Its steering combines poise and precision with effortless action, and the four vented and cross-drilled disc brakes turn in one riveting performance after another. The BMW, despite such advanced features as Active Roll Stabilization and Electronic Damping Control, simply does not have the handling advantage you'd expect.
The 760Li will balk at transverse ridges on the road and transmit the fine details of every divot and railroad crossing through its firmly padded seats. Its longer wheelbase does yield more rear legroom than the S600, but headroom is compromised by a stylishly sloped roofline. The rear seats are divided by an armrest that seems excessively wide, although it does feature a second iDrive controller. The car presents you with a strange mixture of classic luxury, ergonomic overkill, and a host of stylistic idiosyncrasies, such as the optional roof-mounted rear-seat air-conditioning assembly.
Emotionally, these flagship sedans are quite capable of lifting you high above the plebeian masses. From a rational point of view, however, they don't make a particularly compelling case in the value-for-money equation. The $121,205 S600 costs $39,540 more than the V-8engined S500, and the 760Li's $116,495 sticker tops the 745Li's by an astonishing $43,300.
Still, a twelve-cylinder luxury sedan says you've arrived better than just about any other vehicle. The 760Li, which wants to be the sporty alternative to the S600, is a flawed piece, lacking at least 50 horsepower and 146 pound-feet of torque. Its dynamics are not sufficiently special, and the cabin design is incoherent. The 745i and 745Li may be less powerful, but they come off as more honest, harmonious cars.
The S600 is the more rounded vehicle of our pair, although it is hardly perfect. Even when equipped with one of the Designo couture packages ($8900), the S600 still looks and feels more like a C-class on steroids. In terms of ride and acceleration, however, the Mercedes beats the BMW by a significant margin. And next year, the performance gap will widen further when Mercedes releases the 600-plus-horsepower S65 AMG. Is the German car industry's locker-room contest great, or what?