LOS ANGELES – Mercedes-Benz unveils its third-generation CLS at the Los Angeles auto show, announcing the new sedan – which it bills as a 4-door coupe – will go on sale in North America in 2018 featuring a new, inline 6-cyl. gasoline-electric mild-hybrid driveline shared with the recently facelifted S500.

The German automaker confirms three initial models will underpin the new ’18 CLS lineup in its home market, though just one, the initial all-wheel-drive range-topping CLS450 4Matic, is set to kick off sales of the new 4-door in the U.S.

Other new, yet-to-be-confirmed third-generation CLS models, including a rear-wheel-drive CLS350 and all-wheel-drive CLS53 4Matic performance flagship, tentatively are planned for North American introduction, though their sales dates are yet to be announced officially.

With more than 350,000 sales to date, the CLS has proven popular among buyers worldwide. But its popularity recently has waned, due in part to the increasing number of SUV models offered by Mercedes-Benz. As such, the new model, which goes under the internal codename C257, is only planned to be produced in sedan form only.

The CLS Shooting Brake, which has failed to live up to early sales expectations following its introduction to selected markets in 2012, will not be replaced.

As with its predecessors, the all-new CLS relies heavily on the E-Class, from which it borrows its platform, drivelines, chassis, electric architecture and more. Predictably, Mercedes-Benz promises improvements in performance, handling, comfort and safety. At the same time, it says the sedan ushers in a new exterior design lineage to be adopted by other new Mercedes-Benz models in the not-too-distant future.

The ’18-model-year CLS represents a big break from its predecessor in appearance, with the new sedan adopting a brand-new design lineage dominated by what Mercedes-Benz designers describe as the predator face. Also to be featured on other future models from the German automaker, it uses a wide new grille shaped along similar lines to those adopted by more recent AMG models. Canted forward to provide a shark-nose effect, it houses a horizontal blade housing the company’s three-pointed star emblem and a large black plastic insert.

Angular new headlamps taper well back around the front corners. As with the latest E- and S-Class models, they incorporate new LED daytime running light graphics together with multibeam LED projectors with a range of optional adaptive properties.

The flanks eschew the heavily structured treatment used by the second-generation model in favor of smoother forms with greater volume similar to that of the E-Class Coupe and Cabriolet. In a nod to the original CLS, the new model features a subtly bowed beltline, heavily curved roofline, frameless doors and shapely C-pillar design. The haunches over the rear wheel arches also appear more muscular.

The rear continues to be distinguished by a sloping trunk deck, with the organically shaped taillamps of the outgoing model replaced by angular units with lenses creating a crystal effect. They aim to emphasize the new car’s width by extending from the trailing section of the rear fender well into the trunklid.

The retention of the sloping trunk deck as a key design feature challenged Mercedes-Benz’s aerodynamicists, who have developed a new diffuser element rather than resort to an active rear spoiler like that used by Audi on the new A7 in a bid to provide it with the necessary downforce required for sustained high-speed cruising. As such, the overall drag coefficient of 0.26 fails to match the excellent 0.23 of the E-Class sedan.

Mercedes-Benz has yet to reveal the external dimensions of the new CLS, though WardsAuto has been told it has grown beyond the 194.5-in. (4,940-mm) length, 74-in. (1,880-mm) width and 55.9-in. (1,420 mm) height of the outgoing second-generation model, which has been on sale since 2010. The new sedan also is said to feature a 2.4-in. (61-mm) longer wheelbase at 117.6 ins. (2,987 mm) in a move toward larger rear-door openings for easier access to the second row of seats.

To save weight the outer body is made predominantly from aluminum, including the hood, fenders and trunklid. As with the E-Class, though, the frameless doors are fashioned from steel.