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2018 Mercedes-Benz S450

CLIFFORD ATIYEH

Starting a Mercedes-Benz S450 outside the Manhattan Four Seasons could be a letdown, if you’re the type to make it one. Car-enthusiast wisdom says that once you’ve played on the Palisades Parkway in an S65, the base model will forever disappoint. But while the S-class sedan caters to Benz’s most badge-conscious customers, a downlevel numeral on the decklid no longer undermines this big sedan’s reputation.

The Key to a Better Six Life

We first drove the refreshed 2018 S-class months ago in Europe and came away impressed by the two V-8 versions available at that time, the S560 and the Mercedes-AMG S63. Now we’ve driven the first U.S.-spec sedans (they’re arriving at dealers now) and, in particular, this S450 4Matic, which shares its twin-turbo 3.0-liter V-6 with much of the current Mercedes lineup. However, since the 1990s, Mercedes hasn’t convinced Americans to buy gasoline six-cylinder S-class sedans in any significant quantity. The W140 S-class of that era was often compared to a tank for its heavy-duty build quality, and in S320 trim it moved like one—toward the end of that car’s life, the six-cylinder model scored dead last in an April 1998 Car and Driver comparison test. More recently, with the 2010 S400 hybrid, Mercedes paired a larger 3.5-liter V-6 with an electric motor. Cutting a couple thousand off the price of an S550 wasn’t enough to change minds: The six-cylinder S was still too slow. In the last couple of years, though, Mercedes has kept pace with the industry-wide trend of downsizing and turbocharging engines, flooding them with the kind of torque needed to keep a big sedan on its toes—and it is this strategy that finally aligns the S-class with six-cylinder versions of the Audi A8 and the BMW 7-series.

To be clear, the U.S. S450 does not yet pack the brand-new M256 inline-six as sold in Europe. America will have to wait until the next-gen CLS450 arrives to experience that engine, higher trims of which integrate an electrically driven supercharger and a 48-volt electrical system that can generate more than 430 horsepower and adds some basic hybrid functionality. For now, at least, the Yankee S450 carries the current M276 twin-turbo V-6, which generates its 362 horsepower and 369 lb-ft of torque the older-fashioned way. That’s stronger than the 329 hp and 354 lb-ft ratings for the V-6 as used in the E400, although still down a notch from the Mercedes-AMG E43’s 396 horsepower and 384 lb-ft.

What matters is that the S450’s torque curve is as wide and fat as back bacon, with the full allotment on tap from 1800 to 4500 rpm. On the road, this means the 4700-pound sedan is not the lug we’ve come to expect of an S-class with anything less than eight cylinders. Accept the car’s inability to vaporize slower drivers—something the S560 and AMG models do effortlessly—and then realize it still has verve. Mercedes estimates the S450 4Matic can reach 60 mph in 4.8 seconds. That’s 0.8 second quicker than what C/D recorded in a naturally aspirated 5.5-liter V-8 S550 10 years ago, and we tend to beat Benz’s claims. And by the seat of our heated, massaged, and automatically bolstered pants, the new S450 sure feels at least that quick.

The Best at Doing Nothing

That’s in Sport mode. Left in its default Comfort setting, the nine-speed automatic shifts lazily, and the S450 requires a heavy foot to drum up response. As with any softly tuned Benz, the S-class feeds off momentum. It’s for drivers who prefer long, gentle cruises into the night, with the engine humming below 2000 rpm and the silky air-spring suspension and feathery steering gliding them to their destinations. You won’t lust for eight or 12 cylinders while sustaining 100 mph, which the S450 does without strain. See the standing hood ornament? You’ve made it. Relax.

Nowhere is the debate over engine size more irrelevant than inside the S450’s lavish cabin. The standard Energizing Comfort system tailors music, lighting, massage, and cabin-fragrance settings to a preselected mood. That comes across as gimmickry, but the real deal is Intelligent Drive version 4.5, the automaker’s latest semi-self-driving system that we switched on and off during our 300-mile drive. The $2250 Driver Assistance package that brings these features is a steal next to the $5000 Premium package (which includes tech commonly found in fully loaded economy hatchbacks such as a 360-degree camera and proximity entry). When it works, Intelligent Drive is nearly flawless. It obeys dotted highway lines as well as double yellows on main roads, and the Active Lane Change Assist is straight-up freaky the first, second, and even the 15th time you try it by simply activating a turn signal. The S450 may take seven or eight turn-signal blinks before it recognizes nearby cars and slides its big tail into the adjacent lane, but in that time you’ve swigged from a water bottle and changed the radio station.

A Savvy German Still Acclimating to America

Mercedes says its American customers told the company they hated the traditional but clunky cruise-control stalk, and Germany listened. As long as the driver keeps Active Steering Assist and Active Lane Keeping Assist enabled (via two buttons above the headlight dial), the system can be activated with two button taps on the left side of the steering wheel. While not the one-press simplicity of Volvo’s Pilot Assist, this Intelligent Drive is much easier to deploy than the stalk-triggered adaptive cruise control in the 2017 S-class. A third switch engages Active Speed Limit Assist, but on Connecticut’s outdated highways, which post 50-mph limits for no apparent reason, the S-class started to brake while everyone nearby wondered what invisible car had pulled in front of us. We turned it off.

We left all assists off during the majority of our drive, however, because—get this—we like driving. Compared to our brief experience with Intelligent Drive on European roads, we found something was lost in translation while it piloted through urban and suburban routes back home. For every time that the S-class kept calm around a 70-mph highway curve, it would turn a gentle lane change into a game of Pong between the lines, or just plain give up in these more traffic-dense settings. The car would travel uncomfortably close to trucks in stop-and-go traffic and looked as if it might scrub the left side of the Holland Tunnel. Letting the S450 guide itself on the Bronx River Parkway—an intensely narrow, winding two-lane with no shoulders—soon felt suicidal. When traffic stopped for signals, the system wouldn’t brake early enough. The big Benz preferred the Merritt Parkway’s faster sweepers through Connecticut’s Fairfield County—part of a tri-state area that accounts for 20 percent of all S-class sales in the United States—but only when driving slightly above the 55-mph limit. Even when it’s working, you’re always watching it work. So you might as well do something, like take full control.

The irony isn’t about smart cars being dumb. It’s that the S-class has practically driven itself before self-driving cars became trendy. An S-class is among the most effortless and pampering of luxury cars because Mercedes has spent decades and tens of billions of dollars improving it. And now it has a great six-cylinder engine.

Specifications >

VEHICLE TYPE: front-engine, rear- or all-wheel-drive, 4- or 5-passenger, 4-door sedan

BASE PRICES: S450, $90,895;
S450 4Matic, $93,895

ENGINE TYPE: twin-turbocharged and intercooled DOHC 24-valve V-6, aluminum block and heads, direct fuel injection

Displacement: 182 cu in, 2987 cc
Power: 362 hp @ 6000 rpm
Torque: 369 lb-ft @ 1800 rpm

TRANSMISSION: 9-speed automatic with manual shifting mode

DIMENSIONS:
Wheelbase: 124.6 in
Length: 206.9 in
Width: 74.8 in Height: 58.8 in
Passenger volume: 101 cu ft
Trunk volume: 16 cu ft
Curb weight (C/D est): 4550–4700 lb

PERFORMANCE (C/D EST):
Zero to 60 mph: 4.8–5.0 sec
Zero to 100 mph: 11.1–11.2 sec
Standing ¼-mile: 13.4–13.5 sec
Top speed: 130 mph

EPA FUEL ECONOMY:
Combined/city/highway: 22/18–19/28 mpg