Ed Hellwig, Executive Editor
The skiers beside us don't know what to think. One minute they were traversing a catwalk from one run to the other, the next minute there's a $90,000 Mercedes-Benz sedan merging onto the trail like some sort of Bond villain on the run.
They move over, so we ease into the gas again, blowing by in a plume of powder as we make our way down a ski resort access road that crisscrosses several trails along the way. Most people think you need an SUV to pull off a stunt like this, yet we're barreling down the slope in a 2007 Mercedes-Benz S550 4Matic as if it were just another side street.
No one in their right mind would subject their own S550 to such conditions, but Mercedes wants to prove its new AWD S-Class can do more than climb icy driveways. After several runs up and down the mountain on what looks like an oversized bobsled track, the effectiveness of the S550's new 4Matic AWD is obvious.
New system, old name
Mercedes has been offering 4Matic AWD systems for 20 years now. It was an E-Class-only option from '87 to '01, but when the third generation of 4Matic was introduced in 2002 it was added to select versions of the entry-level C-Class and top-of-the-line S-Class.
The 4Matic system in the redesigned 2007 Mercedes-Benz S550 is an all-new fourth-generation setup which, unlike previous systems, was designed entirely in-house. It still uses a center differential to distribute power between the front and rear wheels, but the torque split is now 45/55 front to rear instead of the previous system's 40/60 split.
According to Gunter Fischer, senior manager of development at 4Matic, the revisions to the 4Matic system push its performance past the AWD systems from Audi and BMW. Although Audi's A8 is the only direct competitor to the S550, once this 4Matic system trickles down to Mercedes' E- and C-Class models, it will compete with the BMW xDrive system used in the 5 and 3 Series sedans.
"Our goal was to deliver best-in-class all-wheel-drive performance while maintaining the ride quality and overall refinement of the rear-wheel-drive model," Fischer explained. This means no added gear noise, minimal weight gain and little perceptible difference in handling between a standard rear-wheel-drive S550 and the 4Matic version.
Not much new under the skin
There are a few changes to the S550 4Matic's chassis versus the two-wheel-drive version. The steering rack was repositioned, redesigned suspension arms were swapped in up front and the air springs were retuned. A smaller rear differential is used since there's less power sent through it and there are minor revisions to the brakes. The wheels and tires are exactly the same.
In addition to a center differential, 4Matic adds a front driveshaft to feed power to the front axle. It used to be an awkward setup that required carving out extra room next to the transmission, which ate into the front-passenger foot well. A more compact design of both the driveshaft and the differential allows this 4Matic system to fit within a standard two-wheel-drive chassis with no modifications.
Also, a slightly modified version of Mercedes' latest seven-speed automatic transmission is used and the total weight gain for all the extra hardware is a mere 159 pounds. With 382 horsepower and 391 pound-feet of torque available from the 5.5-liter V8 engine up front, the performance penalty is minimal. If the V8 isn't enough you're out of luck, as 4Matic won't be offered in the S600 or S65 AMG models.
Don't expect to feel a difference
Other than a single badge on the rear deck, it's hard to tell the S550 4Matic from the standard model. The car looks the same when we get in and drives the same, too. Weaving through traffic on the mountains, we never sense any signs of the extra AWD hardware. No wheel binding, no new noises, nothing.
Same goes on the highway. The extra weight isn't enough to slow it down, and the flawless shift quality of the seven-speed automatic transmission is unchanged. Although Mercedes says the 4Matic can accelerate from zero to 60 mph in 5.1 seconds, a rear-wheel-drive S550 we recently tested took 6.1 seconds to do the same, so Mercedes' number looks optimistic.
Even if it's slower than Mercedes claims, the S550 is still plenty fast. It may look big and cumbersome, but it whips through traffic easily. And although the suspension is adjustable, you don't need to fool with it to get a perfectly refined ride. Minimal wind noise, excellent seats and a useful adaptive cruise control system make it almost too comfortable to stay awake.
4Matic does all the work
On tight, icy mountain roads, the only sign of the S550's lack of traction is either a hint of wheelspin on acceleration, or an occasional pulse of the ABS system when braking. Pretty good for a 4,429-pound sedan with nearly 400 horsepower.
Once we get to the snow, the 4Matic's inputs become more obvious. Too much gas and the computer cuts in until the tires catch up. Get into the brakes hard and the system takes over there, too, sometimes a little longer than we would like.
In these conditions we can sense the system moving power from wheel to wheel to find traction, but it's not aggressive enough to be felt through the steering. There's more steering assist dialed in than we remember in the standard S550, but the car is a prototype, so production versions may not feel so light. We hope so, as it's fine for sliding around in the snow, but back on the pavement it feels a little too Lincoln Town Car for our tastes.
Is 4Matic worth it?
Official pricing hasn't been set, but the carmaker said to expect a 2007 Mercedes-Benz S550 4Matic to start around $90,000 when it goes on sale in November, about a $5,000 premium over the standard model. If $85,000 doesn't faze you then $90K probably won't either, but both numbers look steep when you consider the Audi A8L, which starts at a little over $68,000 with standard AWD.
If you don't own a snow shovel, 4Matic isn't worth the premium. It doesn't make the S550 any more sure-footed on the dry pavement, and with the extra weight it's certainly not any faster. Unlike Audi, which likes to think of its quattro AWD system as an enhancement to the car's all-around performance, Mercedes is offering 4Matic purely as a means of attracting snowbelt customers who might opt for an SUV instead.
Considering how it handled that ski slope, your icy driveway shouldn't be a problem.
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