Skip advert
Advertisement

New Mercedes E 400 Cabriolet 2017 review

We try the range-topping petrol version of the luxurious four-seat Mercedes E-Class Cabriolet

Find your Mercedes E-Class
Compare deals from trusted partners on this car and previous models.
Or are you looking to sell your car?
Value my car
Fast, no-nonsense car selling
Value my car

This range-topping Mercedes E 400 is simply too expensive to be the sweet spot of the E-Class Cabriolet line-up, but it has plenty of appeal regardless. It gets a great cabin, excellent top-down cruising refinement and impressive levels of comfort. The torquey diesel-powered E 220 d is expected to be the biggest seller, though, and we can see why, given that it’s only slightly slower in the real world, while also being much cheaper to buy and run.

Advertisement - Article continues below

Summer’s officially over, but that’s unlikely to stop UK buyers from snapping up convertibles in their droves; despite our climate, we buy more drop-tops than the French, Italians and the Spanish.

Mercedes has long enjoyed a slice of this market with cars like the E-Class Cabriolet. The new model is available with two petrol and two diesel engines, and now we’ve had a chance to try the range-topping E 400 4MATIC AMG Line on UK roads.

• Best convertible cars on the market

As in the E-Class Coupe, the E 400 badge signifies V6 power – more precisely, a 3.0-litre twin-turbo unit that we’ve also seen (in more potent form) in the AMG E 43. In this E 400 it has 328bhp and 480Nm of torque, which sounds hefty until you realise that the extra strengthening required to hold the roofless E-Class together has given it a kerbweight of 1,800kg. Lightweight it is not.

So step on the throttle and you’ll find that the E 400 gathers pace with haste rather than in a genuine hurry. It has a claimed 0-62mph time of 5.5 seconds and it just about feels that fast. But the sensation is numbed by the sublime smoothness of the engine, which doesn’t have the subtle rasp that it possesses in E 43 form.

Advertisement - Article continues below
Skip advert
Advertisement
Skip advert
Advertisement - Article continues below

Used - available now

iX3

2024 BMW

iX3

30,852 milesAutomaticElectric

Cash £31,305
View iX3
iX

2025 BMW

iX

53,399 milesAutomaticElectric

Cash £27,552
View iX
i4

2027 BMW

i4

64,403 milesAutomaticElectric

Cash £20,895
View i4
i10

2023 Hyundai

i10

19,611 milesAutomaticPetrol1.0L

Cash £11,971
View i10

Once you’re up and moving, the E 400 Cabriolet maintains its refusal to get flustered – but this brings both positives and negatives. It is incredibly refined; at a fast motorway cruise the nine-speed automatic gearbox barely needs 1,200rpm from the motor, and you simply won’t hear it at that level. This cruising ability is helped further by a multi-layer fabric roof that delivers impressive levels of insulation.

On the downside, the E-Class Cabriolet is far from involving to drive – in the traditional sense, at least. It doesn’t roll excessively, and the steering is responsive enough, but there’s not much fun to be had from a four-wheel-drive chassis that is clearly designed to be faithful to inputs, instead of delivering any kind of thrills. It’s composed almost to the point of banality, in other words.

The ride quality contributes to this, of course. On standard 19-inch wheels, it’s comfortable over all but the roughest roads, and is helped by air-suspension that’s standard on the E 400. Lower the roof and you’ll detect a teeny bit of extra wobble over poorer surfaces, but you’d be nit-picking if you found it a deal-breaker. The cabin stays calm with the lid off, too; you’ll be able to talk to rear-seat occupants without having to shout, and those in the front two seats should be able to chat to each other without turning up the volume at all.

The biggest noise, in fact, comes from the Aircap deflector that pops up from the windscreen. It’s designed to keep buffeting to a minimum, but we’d simply tuck it away. The E 400 also gets Airscarf – warm air blowers in the front headrests that keep your neck warm if you want to drive with the roof down on an autumnal British morning.

The cabin, meanwhile, is every bit as much of a tour de force as it is in the regular E-Class. Material quality is impressive, as is the view from the driver’s seat, with a thick-rimmed steering wheel and a pair of digital displays. Our car had the optional 12.3-inch digital instrument panel, which adds an extra level of luxury – we reckon it’s worth the £495 outlay for the additional screen space and configurability that it offers. Both screens are ultra-crisp and quick to respond to inputs once you’ve acclimatised to Merc’s function-filled COMAND interface, too.

There’s plenty of room for two adults and a couple of kids, although grown-ups are likely to find the rear a little restrictive for longer journeys. The boot is a decent size with the roof up, at 385 litres, which should be enough for a suitcase and a couple of squishy overnight bags. That means you should be able to get to the south of France in comfort, ditch the luggage and then cruise around in fresh-air style – the epitome of what Mercedes’ Cabriolets are about.

Skip advert
Advertisement
Editor-at-large

John started journalism reporting on motorsport – specifically rallying, which he had followed avidly since he was a boy. After a stint as editor of weekly motorsport bible Autosport, he moved across to testing road cars. He’s now been reviewing cars and writing news stories about them for almost 20 years.

New & used car deals

Omoda 5

Omoda 5

RRP £24,040Avg. savings £1,761 off RRP*Used from £15,550
Dacia Spring

Dacia Spring

RRP £11,990Avg. savings £703 off RRP*Used from £10,649
Audi A3

Audi A3

RRP £10,770Avg. savings £2,811 off RRP*Used from £10,770
MG MG4

MG MG4

RRP £11,000Avg. savings £3,079 off RRP*Used from £11,000
* Average savings are calculated daily based on the best dealer prices on Auto Express vs manufacturer RRP
Skip advert
Advertisement

Most Popular

Honda CR-V prices slashed by thousands, ZR-V gets cheaper too
2026 Honda CR-V - front cornering

Honda CR-V prices slashed by thousands, ZR-V gets cheaper too

Honda has revealed updated pricing for the CR-V and ZR-V models, with the latter getting a particularly chunky discount
News
2 Nov 2026
New Renault Megane to take on the Tesla Model Y with a radical makeover
Renault Megane - front quarter exclusive image Avarvarii

New Renault Megane to take on the Tesla Model Y with a radical makeover

Hi-tech ‘software-defined’ C-segment model heralds a new design direction for Renault as the firm works to achieve a 465-mile range
News
2 Nov 2026
New Fiat Topolino Dolcevita arrives as dinky electric convertible for £9,500
Fiat Topolino Dolcevita - front 3/4

New Fiat Topolino Dolcevita arrives as dinky electric convertible for £9,500

The cute electric quadricycle can now be ordered as a convertible for a small additional outlay
News
3 Nov 2026