The Mercedes-Benz E-Class Cabriolet has a strange and winding 25-year history. It all started with W124-generation cars in the early 1990s, the first Mercedes models to bear the E-Class name. In the late 1990s, the E begat the CLK-Class Cabriolet for two generations, both of which were based on the compact C-Class but sold as high-style (and price) premium models. When Mercedes middle child droptop switched back to the E-Class name in 2010, this convertible still carried the dirty little secret that the platform was C-Class while the interior was modified E-Class.

For 2018, it becomes a true E.

That means it gets longer and wider, as well as more opulent and packed with more technology.

A capital E

The Cabriolet is the fourth and final body style in the redesigned W213-generation E-Class lineup. It started with the sedan, and moved on to the wagon, the coupe, and now the droptop. Closely related to the coupe, the Cabriolet shares that two-door’s 113.1-inch wheelbase and 190-inch overall length. Those numbers are 4.4 and 4.8 inches longer than those of the outgoing car, and it is 2.9 inches wider, too.

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2017 Mercedes-Benz E-Class (E300)

2017 Mercedes-Benz E-Class (E300)

2018 Mercedes-Benz E400 Coupe

2018 Mercedes-Benz E400 Coupe

2017 Mercedes-Benz E400 Wagon first drive

2017 Mercedes-Benz E400 Wagon first drive

The extra length has the greatest effect on interior space. The rear seat gains an amazing 3.9 inches of leg room, and all seating positions add shoulder room as well.

With the top chopped and a bigger cabin area to cover, it was important to reinforce the E-Class Cabriolet’s structure. Mercedes added an X-brace to the front of the underbody and a Y-brace to the rear. More substantial rocker channels are the gift the convertible gave to the coupe. Additional sheet metal was added in the rear fender area over the wheel wells, and the front structure received a vertical brace in the shape of a W.

That’s not the end of the structural story. The E-Class Cabriolet’s unibody uses a combination of high-strength steel and aluminum to optimize both weight savings and strength. The wheel wells, hood, trunk, and fenders are all aluminum.

European vacation

To show off the capabilities of its new droptop, Mercedes invited Motor Authority to drive the E Cab like a well-to-do European owner might on summer holiday: through the French Alps to Italy and back through France to Geneva. Not a bad little drive, thank you very much.

American buyers get the E Cab in just one model to start—E400—though more powerful versions are almost certain to follow. The E400 features Mercedes’ twin-turbocharged 3.0-liter V-6, here spinning out a silky 329 horsepower and 354 pound-feet of torque. It sends its thrust through a smooth-shifting 9-speed automatic transmission to either the rear wheels or all four via Mercedes’ 4Matic all-wheel-drive system.

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

A steel spring suspension is standard. The E Cab sits 0.6 inch lower than the sedan. Mercedes makes a multi-chamber air suspension—two chambers up front, three in the back—available as well. It comes with electronically controlled dampers, and it can firm up the suspension to reduce body lean or soften it for greater comfort. Both of the cars I tested had the air suspension, as well as the optional 20-inch wheels and an AMG Line package with AMG body styling, a sport steering wheel, a black headliner, and aluminum pedals.

A standard Dynamic Select system adjusts the dampers, air suspension, throttle, start/stop function, and shift points. It has Comfort, Eco, Sport, Sport+, and user-programmed Individual modes.

Since it was a beautiful day in France, I dropped the top, left the Drive Select in Comfort mode, and headed for the mountains by way of Annecy and Chamonix, France.

The E-Class isn’t the car it used to be. That’s both good and bad, depending on your perspective. Mercedes has injected a bit of sportiness into what has traditionally been a decidedly luxury-oriented car, and that’s where the effort to strengthen the chassis has paid off. While this car feels solid with the top down, its sheer size means it still has some cowl shake over broken pavement.

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

That doesn't detract from the experience, though. The steering is light and direct, but not overly quick. The car turns in responsively and has a somewhat playful character. Comfort mode, however, dulls the senses, introducing a bit of throttle and shift lag and making the ride motions a tad unsettled.

Sport mode tidies up those issues without going too far. It makes the throttle and transmission more responsive, and ties down the suspension to create a sportier driving experience with surprisingly little body lean. Skip the Sport+ mode entirely; it’s way too aggressive for this cruiser.

In any mode, the ride is usually quite smooth, but the 20-inch wheels and low-profile tires (245/35s up front, 275/30s out back) cause the suspension to send some unpleasant jolts into the cabin when driving over sharper bumps. The 20s may look cool, but stick with the base 18s or perhaps the optional 19s.

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

All-weather convertible

Mercedes wants to make the E-Class Cabriolet a four-seasons convertible, and the brand keeps throwing equipment at the car to do just that. The top mechanism is almost enough in itself. It opens or closes in 20 seconds with the push of a button at speeds up to 31 mph. The soft top is layered and insulated to shut out the elements and the wind, and it does a great job of both.

Mercedes offers some features to make it palatable to put the top down even when the weather isn’t perfect. The AirScarf neck-level heating system warms the cabin with the top down in cooler temperatures, and the AirCap system routes wind over the car to reduce interior wind turbulence and allow normal conversation.

With a larger interior to deal with this time around, Mercedes’ engineers had to tweak AirCap to make it as effective as it was for the last-generation model. AirCap consists of a pop-up air deflector in the windshield header and a pop up wind blocker behind the rear seats. It is fairly effective on its own, but if you really want it to work—for instance, to keep a lady’s floppy hat from getting blown about—you have to roll up the windows, too. That’s a concession to aerodynamics, but I think driving a convertible with the top up is the automotive equivalent of wearing black socks with sandals. Nonetheless, that’s how I drove the E Cab—in deference to my passenger’s floppy hat.

Mercedes added a few more all-season and utilitarian features for 2018 to make the car 365-day viable. The 4Matic all-wheel-drive system is offered for the first time on an E-Class Cabriolet, the leather has heat-reflecting properties to not scald bare legs on a hot day when wearing shorts or a skirt, and the rear seats now fold down in a 50/50 split to make the decent-sized trunk (no U.S. cargo measurement is available yet) more luggage-friendly. I also found the cooled seats to be a help on my trip through the mountains as the day grew hotter.

Inspired by yachts

Mercedes says the interior design was inspired by yachts—one of available interior colors is even called yacht blue. That’s appropriate in more ways than one. The driver’s seating position is notably low and boat-like. Perhaps bathtub-like is the better term. The high beltline makes it hard to see to the corners, especially for smaller drivers and that’s not helped by the driver’s seat, which could raise a bit higher.

Back seat passengers will be almost as comfortable as those up front. The E Cab accommodates two in the back and they have plenty of head room and leg room with the top up or down. In fact, The E Cab has more rear leg room than the larger S-Class Cabriolet.

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

Interior materials are of the highest quality and the design is stunning. The line the runs around the circumference of the cabin is reminiscent of high-end boats, the air vents look like miniature turbines, and the dash is slathered in leather, aluminum, and wood. Mercedes offers 64 colors of ambient lighting to highlight the details, and the dashboard comes with at least one if not two 12.3-inch screens. When two are ordered (the second is in place of the instrument panel), they come together as one mammoth digital interface.

2018 Mercedes-Benz E400 Cabriolet

2018 Mercedes-Benz E400 Cabriolet

Somewhat incompatible with the mission of a convertible is Mercedes suite of autonomous driving functions. The E-Class Cabriolet can follow a vehicle ahead at speeds up to 130 mph, follow the road when the lane markings aren’t clear at speeds up to 81 mph, change lanes for the driver once the turn signal is activated, and apply the brakes and amplify steering inputs if it detects an impending crash. Thankfully for those who like to drive, the autonomous functions have to be turned on via the steering wheel, but the safety side of those features is always operational. I made use of none of these features in my trek through the Alps to Mont Blanc.

Then again, perhaps those autonomous driving functions aren’t anathema to the 2018 Mercedes-Benz E-Class Cabriolet. This is the first true E Cab in a generation, after all, and it should have all the tech of the other E-Class body styles, along with the room of a mid-size car, the top-up isolation of a sedan, and the power and handling of its siblings—all while offering the pleasure of top-down driving.

For a price of roughly $68,000 ($71,000 with 4Matic), the 2018 Mercedes-Benz E-Class Cabriolet delivers on these promises and more. It is a true E, and it is one fine way to drive through the French Alps in June.

Mercedes-Benz provided travel and lodging to Internet Brands Automotive to bring you this firsthand report.