Who needs a chauffeur? Mercedes' plush S550, with options, almost drives itself
Sep 22,2006 00:00 by Mark Maynard

For those commuters too busy to drive as they check sports scores, trade stocks or watch a movie on their phone, Blackberry or DVD screen, Mercedes-Benz has an upgraded cruise control that keeps electronic eyes on the road.

MERCEDES S550 - The Mercedes S550 has short- and long-range radar that can scan 160 yards ahead and be active at speeds up to 120 mph. At slow speeds, the system will brake the car to a stop. CNS Photo courtesy of Mercedes-Benz.
Adaptive cruise control isn't new, but the evolution of this system is - to be used in stop-and-go traffic, not just interstate travel. Now with short- and long-range radar, Mercedes' Distronic Plus can scan 160 yards ahead and be active at speeds up to 120 mph. At slow speeds, the system will brake the car to a stop, then apply the throttle as traffic begins to move again, always keeping a preset distance from the vehicle in front.

The car does not drive itself - yet - and hitting the brakes returns all functions to driver control, which Mercedes emphasizes is how it should be.

There is much to learn about the many options available on the redesigned S550 sedan.

Among them:
  - Radar-assisted rear parking assist, $750, shows outlines of your intended path and how to turn the steering wheel to guide this 17-foot-long sedan into a spot. It also alerts you when there isn't enough room.
- Brake Assist Plus, to prevent rear-end collisions. Short-range radar monitors distance from the vehicle ahead and relative speed, then increases the intensity of the driver's braking if there is risk of a rear-end crash. Packaged with Distronic Plus, $2,850.
- Pre-Safe Brake. Activates braking in two stages if the driver doesn't and an accident is unavoidable. If the driver still doesn't respond, then Stage 2 activates the emergency braking of Brake Assist Plus. It is standard equipment with the Pre-Safe system that activates all systems in the event of an impending crash. Seat belts are pretensioned, side windows are raised, the sunroof is closed, seat backs and cushion angles are adjusted, side bolsters are inflated and rear headrests are raised.
- Night View Assist. Infrared light imaging allows the driver to see clearly in black and white up to 500 feet ahead. When switched on, the image is displayed on an 8-inch screen at the speedometer in the instrument cluster. The imaging is unnecessary in well-lighted urban areas, but for those who travel dark back roads, it could be worth the $1,775 price.
- Active Curve Illuminating Headlights. Bi-xenon headlights (an option) move with the steering wheel to put light deeper into curves.

These enhancements are not cheap.

The S550 has a starting price of $86,175, which is $650 less than the '05. The price includes $775 for freight, but not the $1,000 gas guzzler tax. The test car with options was $98,150. That's a lot of money, but sales so far are up 104 percent over last year, which totaled 16,000 as of July.

The fleet and flowing shape of this big Benz doesn't exaggerate any one feature but gives the perception of expensive jewelry. And the test car was made more dramatic with the AMG sport package. The pricey package - $5,600 - adds 19-inch wheels, lower aero body extensions and hefty chrome exhaust tips, but no performance boost.

And, really, most users won't be displeased with the 382-horsepower, 5.5-liter V-8 and seven-speed automatic with steering wheel shift buttons. The power rolls on hot and thick with lush shift points and a hearty exhaust note. Fuel economy is a respectable 16 mpg city and 24 highway on 91 octane.

The only other engine choices are the 510-hp, 6.0-liter V-12 in the S600 - $140,675 - no options, just pick the color. Or the ultra S650 - $182,275 - with the AMG performance treatment of twin-turbo V-12 for 604 horsepower, 738 foot-pounds of torque and 0-60 mph in about 4.2 seconds.

 The sophisticated styling doesn't go unnoticed inside, either. At night, a line of mood lighting spans the dashboard, to the doors and into the back. Leather, walnut trim, aluminum switches and metal-coated controls enhance without looking gilded. And there's nothing so prissy that would exclude children and the wear and tear of family duty.

There is full-bodied seat capacity, and I like the smooth opening of the doors and how they stay open at any angle, without lunging from one spring-loaded detent to the next. How civilized, and so are the electric closers. The driver also has the "chauffeur" button to move the passenger seat fore and aft when picking up colleagues. The only annoyance was the loud, incessant tone of the seat-belt reminder.

There's more rear legroom than in the front seat, depending on how tall the driver is. As with most of these big luxo-cruisers, the center back seat position is compromised by a tall transmission tunnel and a seat that sits high and forward. The window seats are always the better spot.

The electronic COMAND networking of in-car controls - radio, seats, navigation, etc. - has evolved for more user-friendliness. I figured it out without reading the owner's manual.

Settings are accessed by a large dial on the center console, in just the place where your right hand falls, to page through settings. Choices are displayed on a large screen high in the center instrument console. There also are buttons for frequently used features, such as the fan and radio-CD, which has a volume control wheel next to the dial.

Those who live in hot climates will appreciate the optional ventilated seats with electric fans that circulate air through the seat cushion and backrest. A "summer opening" feature switches on the vents, opens the windows and sunroof via the keyless remote. No more scorching leather and saunalike cabin on August afternoons.

This is a large car, but it drives much smaller. Steering force is fingertip-smooth, even at slow speeds, which helps the car feel light and manageable. The Airmatic adaptive damping suspension uses pneumatic struts and umpteen sensors to balance stiffness and control, with comfort and sport settings.

If you prefer soft and comfy, this may be too Euro-responsive. The system lowers the car three-quarters of an inch at speeds over 68 mph and it can be raised 1.2 inches over rough road.

The S550 is an impressive flagship, but for those unaccustomed to a car that thinks, embracing its many electronic interventions may take time, yet it might be a more attentive driver than most humans.

Copley News Service

2007 Mercedes-Benz S550
Body style: Large, 5-passenger, long wheelbase, rear-wheel-drive sedan; aluminum front fenders, doors, hood and trunk lid
Engine: Aluminum, 382-horsepower, DOHC 5.5-liter V-8 with variable valve timing
Torque: 391 foot-pounds at 2,800 to 4,800 rpm
Transmission: 7-speed automatic with steering wheel shift buttons
Acceleration: 0 to 60 mph, 5.4 seconds
EPA fuel economy estimates: 16 mpg city, 24 highway; 91 octane required
Fuel capacity: 23.8 gallons

Trunk space: 16.3 cubic feet
Front head/leg/shoulder room: 37.8/41.9/59 inches
Rear head/leg/shoulder room: 38.5/42.3/58.7 inches
Length/wheelbase: 205/124.6 inches
Curb weight: 4,465 pounds

Standard equipment includes: remote locking, dual-zone automatic climate control, full-leather upholstery, wood trim, 14-way adjustable front seats with memory presets (including steering column and outside mirrors), 14-speaker Harman Kardon Logic7 surround sound audio system, 6-disc CD changer and memory card slot, power rear sunshade, power glass sunroof, infrared reflective and noise-insulating glass, rain-sensing wipers, bi-xenon headlights with active curve illumination, fog lights, GPS navigation system, electronic parking brake, digital tire pressure monitoring system, power door and trunk closers
Safety equipment includes: 8 air bags with 10-way protection, including full-length head protection, 4-wheel ABS with brake assist and electronic stability program

Brakes: power-assisted 4-wheel vented discs, 4-channel ABS and Brake Assist Plus
Steering: speed-sensitive, power-assisted rack-and-pinion; turning circle, 40 feet
Suspension: four-wheel independent with Airmatic adaptive damping, driver-selectable ride height and automatic lowering at higher speed; gas-charged shock absorbers and stabilizer bars front and rear
Tires and wheels: 255/45 HR 18-inch all-season on alloy wheels

Base: $87,175, including $775 freight charge and $1,000 gas guzzler tax; price as tested, $98,150
Options on test car: rear view monitor, $750; Distronic Plus, $2,850; night view assist, $1,775; AMG sport package, $5,600, includes 19-inch 5-spoke light alloy wheels, aero body trim and chrome exhaust tips
Warranty: 4 years/50,000 miles with roadside assistance
The competition: Audi A8, BMW 7-Series, Jaguar XJ, Lexus LS 460
Where assembled: Sindelfingen, Germany

PLUSES: More style and finesse than ever before, but not gilded. This is luxury with function that will withstand the wear and tear of family use.

MINUSES: Loud and sharp seat-belt reminder tone; tall center drive-shaft tunnel compromises rear center seat foot room for a seat that's not all that comfortable.