Expert Reviews

Test Drive: 2018 Mercedes-Benz E400 Cabriolet

8.3
10
AutoTrader SCORE
This score is awarded by our team of expert reviewers after extensive testing of the car
  • STYLING
    9/10
  • Safety
    9/10
  • PRACTICALITY
    7/10
  • USER-FRIENDLINESS
    8/10
  • FEATURES
    8/10
  • POWER
    8/10
  • COMFORT
    9/10
  • DRIVING FEEL
    9/10
  • FUEL ECONOMY
    8/10
  • VALUE
    8/10

If you consider motoring comfort to be a dish best served topless and twin-turbocharged, you’ll want to make arrangements to check out the newly available 2018 Mercedes-Benz E400 Cabriolet, lickety-split. And for your test drive, devise a route that includes both a highway and the roughest available nearby road, to quickly see the machine’s two most valuable assets in action.

Rough roads feel smooth, and smooth roads and highways feel like they’re not even there.

Those two assets? Ride quality and the highway cruising experience.

Specifically, the E400’s ride quality shines on rough, real-world asphalt. The crumbling, poorly built roads of Sudbury, Ontario, are the paved, pothole-marked definition of “worst case scenario” for ride quality – and I don’t often come across vehicles that do this good of a job at remaining this comfortable on roads this poor in shape.

The E400 Cabriolet’s ride stays quiet, composed, and beautifully isolated, with a dense and durable feel almost no matter what’s beneath. Wince-inducing bumps and dips barely register. Big dips and whumps that often send occupants for a tandem toss-about cause scarcely a squirm here. Even accidentally cranking a railway crossing that had lifted out of the decaying road beneath, there was little noise, little harshness, and little thought of “Crap, that definitely broke something.”

The adaptive suspension system to which my tester’s body was bolted is a gem: it nukes excessive body movements before they manifest, ensures consistent comfort at all times, and turns in the sort of ride you’d expect from a four-wheeled land-barge with a gravy-based suspension, all without handling like an overloaded custard truck.

So, rough roads feel smooth, and smooth roads and highways feel like they’re not even there. It’s clever engineering and technology deployed towards absolute comfort, and that’s an ongoing theme for this machine.

Said machine is the latest take on the new E-Class, which has traditionally been available as a sedan or wagon, but has now come online in two-door variants for more selection. You can have an E-Class Coupe, or the tested Cabriolet variant. Both offer the space and amenities of a world-class luxury sedan, applied to a big two-door package, roof-optional in this case.

This car is good at many things, but it’s the best at one specific thing: turning in very comfortable, effortless, and relaxing long-haul motoring.

A few notes on how that pans out.

Top-down noise levels are louder, but kept decently in check and warrant little need to shout to communicate with nearby passengers, even at highway speeds. The 3.0-litre twin-turbo V6 is gushing with invisible torque: you don’t realize the engine is there much of the time since it’s rarely audible, and you virtually never feel it. Even the idle-slashing auto stop-start system is among the quietest and smoothest on the scene.

With some of the most advanced autonomous systems available, the E400 Cabriolet can automatically maintain a safe following distance, self-steer to stay in its lane perfectly or to navigate corners, or even execute hands-free lane changes. For the latter, just tap the signal, and the car scans blind spots via radar, and moves over with no need to touch the steering. It all gives drivers one less thing to do, other than sitting back and soaking up the sun and scenery.

All-wheel drive (AWD) is standard if you’ll be out and about in the winter, and with the roof up, the cabin is so quiet and well-insulated that you’d hardly know you weren’t in a big, fixed-roof coupe. Cruising at a good clip, it never sounds like you’re in a four-wheeled tent. This one’s a swanky luxury two door you can use all year round, and one that’s ready for top-down road trips on a whim.

Rear seats are a tad snug but adult-friendly, a cinch to board and exit (especially with the roof down), and heated. Behind them, a motorized wind buffer appears at the touch of a button, reducing turbulence and noise. Another button tap instantly rolls all windows down for a fully open motoring experience, or rolls them all up at once for cruising in realtor mode (top down, and all windows up).

AirScarf heaters on the front seats breathe warmth around occupants’ necks, which is inviting on chilly days. Conversely, if you’re a sweat factory of sogginess when it’s hot, the air-conditioned seats effectively fend off Niagara Falls–levels of back sweat for the duration of your drive. Nearby, there’s adequate at-hand storage and charging provisions for mobile devices, which can be stored in an air-conditioned console or glovebox to prevent battery-killing overheating on hot days.

Ditching the roof is a cinch: stop the car, hold a little switch, enjoy a few moments of hinge gymnastics and tensioning-wire jujitsu, wait for the beep, and off you go. The E400 Cabriolet’s cargo hold will accept a few carefully packed bags or a load of groceries, and a divider flap can be opened to expand trunk space when the roof is up. With it down, a pair of gym bags or two items of luggage should fit nicely, though overall cargo space is slashed.

In all facets of very, very comfortable convertible motoring, the E400 Cabriolet backs owners up with little less than a full selection of the best characteristics on offer in the segment today.

It’s swathed in a package drenched with upscale touches and detail work. Don’t miss the jewel-spackled inserts in the taillamps, the illuminated Mercedes-Benz graphic in the headlamps, the intricate, AMG-inspired front fascia, or the open-pore wood that dresses up the dash, itself dotted and lined with precisely applied metallic trim and glossy consoles. Taken as a whole, with swank galore and two large displays comprising the instrument cluster and central command interface, the E400’s cabin looks one-part futuristic spaceship and one-part luxury flagship – thanks to numerous elements borrowed from the big-Kahuna S-Class.

The turbo V6 performs adequately, with plenty of low-end torque for quiet, low-revving responsiveness. If you think 400 hp is a bit much, but that 275 horsepower is a few less than anyone who likes horsepower will need, then you’ll probably consider the E300’s output of 329 ponies to be sensibly adequate.

Opened up, acceleration is brisk but won’t light your face on fire, and the sound of the engine, which is all but inaudible below very high revs, is dull, quiet, and adds little to the experience. Taken as an entire system, this powertrain is most impressive when used gently.

Steering has an accurate and light feel, but lacks any meaningful feedback regarding what’s happening between the tires and the road. When tossed around some corners, the E400 Cabriolet doesn’t feel bothered, or excited. Various drive modes can be deployed, some of which dial up sportiness, responsiveness and suspension stiffness – but here’s a machine so good at the comfort thing that you’ll likely never bother much with the Sport or Sport+ modes.

Four additional notes.

First, if you’re considering adding an E400 to your driveway alongside an existing, recent E-Class sedan, you’ll feel right at home in the lap of effortless and serene luxury. Both cars have the same personality.

Second, headlight performance is exceptional, with potent light output landing among the best I’ve ever used.

Third (and weirdly worth reporting), the driver footwell is wide and spacious. There’s sufficient room for those who love a good wide-legged sit, and it may add comfort for limited-mobility drivers who may have recently received a new hip or knee.

Fourth, maneuverability is excellent, thanks to a smaller-than-you-think turning circle, and the best graphics I’ve ever seen on a camera parking system. This one’s a total breeze to move around in tight quarters.

Gripes were mostly minor, other than the really big one, which relates to the lane-departure system.

At times, when moving over to leave room for a roadside cyclist or parked car, an un-signalled swerve over the centre line may see the vehicle apply hard braking and nudge the steering back towards the car or cyclist you’re trying to leave room for. The steering input here is slight and easily overcome, but the whole thing can be alarming and frustrating. I wound up turning it off.

Further, the central command interface is slick and vivid, but will require an afternoon of practice before you’re using it with ease. Finally, the column-mounted gear shifter sits where every other car has their wiper stalk, meaning you could, feasibly, try to engage Park when attempting to, say, clean the windshield, so do be careful.

I’ll leave you with this: if you’re after a long-distance ready luxury convertible that’s laser-focused on delivering tranquil, top-optional drives, this might very well be the best choice on the market right now.

Specifications
Engine Displacement 3.0L
Engine Cylinders V6
Peak Horsepower 329 hp @ 5,250–6,000 rpm
Peak Torque 354 lb-ft @1,600–4,000 rpm
Fuel Economy 12.0/9.2/10.8 L/100 km cty/hwy/cmb
Cargo Space 385 L
Model Tested 2018 Mercedes-Benz E400 Cabriolet
Base Price $80,300
A/C Tax $100
Destination Fee $2,495
Price as Tested $95,695
Optional Equipment
$12,800 – Premium Package $4,800; Intelligent Drive Package $2,700; Technology Package $2,600; Sport