• 3rd-gen version of the original “coupe” sedan arrives in late 2018
  • Powered by a new inline-6 with electric assist
  • Loaded with advanced safety technologies
  • Seats five for the first time
  • New AMG model coming: the CLS53

When the 1st-generation Mercedes-Benz CLS arrived in 2004 it made a huge splash as a stylish 4-door sedan with a coupe-like roofline, an arching beltline and frameless side windows. That original CLS, a stylish 2+2 based on the E-Class, was such a hit that it spawned imitators and effectively created a whole new genre of coupe-like sedans. While the 2nd-generation CLS introduced in 2011 had nowhere near the impact of the original, the new 2019 Mercedes-Benz CLS450 that goes on sale in the U.S. this fall looks poised to recapture some of that early magic.

Two reasons. First, the 2019 CLS looks great. It’s lower, wider and more aggressive than the 2nd-gen car, with Mercedes’ new “Sensual Purity” styling very apparent in the minimal character lines and creases of the new CLS. Second, the 2019 Mercedes-Benz CLS is powered by a new engine, a turbocharged 3.0-liter inline-6 with an Integrated Starter-Generator that adds up to 21 horsepower when needed.

The new inline-6 engine

That’s right, an inline-6. It has been 20 years since Mercedes offered a straight-6 in a car (the big S320 sedan of 1998), and this new powerplant is a technical marvel. In basic description, it’s a compact aluminum-block 3.0-liter straight-6, with two overhead camshafts, four valves per cylinder and all the expected smoothness of that inherently balanced configuration. What’s more, it’s turbocharged, which helps it produce a healthy 362 horsepower at 5,500 rpm and 369 lb-ft of torque from 1,600 to 4,000 rpm.

Mercedes fits this new 6-cylinder engine with an Integrated Starter-Generator. The powerful EQ Boost electric motor, mounted inside the engine’s bellhousing, adds 21 horsepower and 184 lb-ft of torque to the CLS450 engine’s output for short periods, primarily at launch. This motor, powered by a 48-volt electrical system, also serves as the engine’s starter, which provides the added benefit of making the fuel-saving automatic start/stop system of the new CLS the smoothest we’ve felt in any Mercedes.

Also noteworthy: In certain situations (Eco mode, stop/start not defeated), when the driver lifts completely off the throttle on the highway, the new Mercedes 6-cylinder engine will shut down and allow the CLS to coast or “sail” down the road to save fuel. But at the very moment the driver ever so slightly dips back into the throttle, the engine automatically restarts to resume propelling the new CLS450 merrily down the road. Again, the automatic start/stop process is so smooth that it may go can go unnoticed if you’re not monitoring the tachometer.

Another cool detail: The 2019 CLS’s engine, which mates to a 9-speed automatic transmission with paddle shifters, has no traditional belts. To reduce parasitic losses (and thereby save fuel), items such as the air conditioning compressor, the power-steering pump, and even the water pump are all electric. The 48-volt battery, for the record, is in the engine compartment, with the conventional 12-volt battery.

Also: Get your first look at the new and redesigned cars of 2019

The Interior

Although Mercedes likes to tell us the new 2019 CLS450 is a now a 5-seater with an extra half-inch of leg room, not many people will want to sit in the middle back seat -- let’s just say it’s best for kids. But that should not detract from what is an otherwise excellent interior, one that’s comfortable, well equipped and handsomely stylish, with attractive exposed-grain wood trim and sweeping shapes influenced by the exterior lines of the car.

Taking center stage is the configurable and fully digital “Widescreen” cockpit, which features a 12.3-in. high-resolution screen as the central display, plus another 12.3-inch optional screen behind the steering wheel and serving as a tachometer and speedometer. One large single panel of glass covers both of these horizontal screens, which relay information clearly and look as if they might come from Apple’s iPad supplier. Whatever the case, the screens are effectively shielded from the sun by a stitched and padded leather hood.

While multiple controls are found on the CLS450 steering wheel (some redundant with the COMAND central controller), they are all nicely integrated into the thumb panels. The center console is wide but not intrusive, and the multipurpose COMAND controller is perfectly situated for the driver’s right hand. The seats have large bolsters for side support, but they also provide long hours of comfort, with adjusters on the door panels making on-the-fly adjustments easy.

And kudos to Mercedes for having some fun inside the new CLS: When the temperature of the climate control is raised, the turbine-like vents on the dash briefly turn red. When cooler air is requested, they briefly turn blue. It’s fun, as are the 64 colors of ambient lighting available inside the new CLS. Continuing the fun, the 2019 Mercedes-Benz CLS450 also offers Energizing Comfort, a new system designed to promote driver wellness via functions related to climate control, fragrancing, heating, ventilation, lighting, and the massaging front seats. While some people will use the Energizing Comfort features, we suspect more will enjoy Apple CarPlay, which is standard on the 2019 CLS450.

Intelligent Safety

Mercedes says the new CLS has much in common with the new S-Class sedan. This includes the latest generation of driving-assistance systems featuring Active Brake Assist, Attention Assist and Pre-Safe Braking all standard.

Not standard, but optional, is an extensive multi-function Driver Assistance Package. This $2,250 Driver Assist Package includes active cruise control, steering assist, speed limit assist, and active brake assist (with cross-traffic function). On top of that, it has evasive steering assist, active blind-spot assist, lane-keeping assist, and Pre-Safe protection in frontal and side collisions. Of note: If a lateral collision is deemed imminent, Pre-Safe will preventatively move the driver or front passenger up to 2.75 inches away from the impact zone by rapidly inflating the seat’s side bolster. Also, Mercedes says its active cruise is now much better, thanks to improved camera and radar systems, plus a new ability for the vehicle to adjust its speed prior to bends or junctions.

What’s it like to drive?

In a word, great. The 2019 Mercedes-Benz CLS450 4Matic is a well-built automobile, a solidly constructed machine that doesn’t feel like a sedan from the driver’s seat. It feels low and wide and quick, but not by any means a dragstrip challenger for, say, the E63 sedan or wagon, which are both powered by twin-turbo 4.0-liter V8s.

Where the inline-6 impresses is with its smoothness and linear power delivery. Press the accelerator pedal, and there’s a smooth ramp up of power, almost as if the engine weren’t turbocharged. The shifts that follow are especially smooth (almost unnoticeable) in the Comfort drive setting, but they firm up nicely in Sport or Sport +. The ride quality on smooth roads is good, as is the overall composure of the chassis on twisty highways. On the down side, the chassis response to a couple of surprise potholes in New Jersey and New York felt harsh at best. I found myself wishing the CLS had higher-profile tires.

Apart from that, all felt good. The chassis, aided by 4Matic all-wheel drive, can take a lot of throttle out of corners, and the CLS cruises quietly at highway speeds, making long trips feel short. Braking response and steering feel natural, and it’s fun to experiment with the new coasting feature: If you’re on a slight downhill, the engine will stay shut off for quite some time because the CLS maintains highway speed pretty well. But on level roads or highways, it’s off for a much shorter time because the CLS slows down more quickly and needs to get back up to speed sooner.

More: 2019 Car Reviews: First takes on new models


Although we don’t have official pricing on the 2019 Mercedes-Benz CLS450 yet, KBB has been told it will start in the low $70,000 range, with 4Matic adding approximately $2,000. We also have some of the option prices. Here are some highlights.

Burmester High End 3D Surround Sound audio system: $5,400
Air Body Control suspension: $1,900
Driver Assistance Package: 2,250
Upgraded Nappa Leather: $1,370
Premium Package: $3,150
Acoustic Comfort Package: $1,100
Head-Up Display: $990
Parking Assistance Package: $1,290
12.3-inch digital instrument cluster: $850
Energizing Comfort Package: $550


Coming Soon: The CLS53 AMG

We’ll leave you with a look at the AMG version of the new CLS, the 2019 Mercedes-AMG CLS53, which arrives this fall at the same time as the CLS450.

What makes the CLS53 so special? As expected, it has the turbocharged 3.0-liter inline-6 of the standard CLS450, along with the Integrated Starter-Generator, but its engine has been modified by AMG with an electric auxiliary compressor. In other words, the AMG CLS53 is fitted with an electric supercharger, which helps low-rpm power and bumps overall power output to 429 horsepower and 384 lb-ft of torque, making the new CLS53 a good competitor for the Audi S7.

Besides its electrically supercharged engine, the 2019 Mercedes-AMG CLS53 is set apart by its AMG Speedshift 9-speed automatic transmission, an AMG steering wheel, AMG-tweaked 4Matic all-wheel drive, special seats, and AMG Ride Control air suspension with continuously adjustable damping.

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