Mercedes-Benz E400 vs Mercedes-Benz GLC-Class

What's the difference?

A convertible that doesn't feel like one when the roof is in place is no easy task to build, but it's one Merc's engineers have pulled off with the E400 4Matic Cabriolet. Effortless power, a tonne of technology and a comfy, leather-wrapped cabin all make Merc's drop-top E-Class a strong proposition.

Like I said right from the start, this new, hybrid version of the AMG GLC63 is technically superior to the model it replaces in every meaningful way. It is faster, more powerful and more fuel efficient and therefore a better performance SUV than the model it replaces.

Is it a better model than the one it replaces? Ultimately that will come down to how much stock you put into the soundtrack and your feelings on an AMG not powered by a V8 engine.

Because if you can see past that, then the AMG GLC63 is an absolutely fantastic performance SUV. Not only does the new powertrain make it faster in a straight line, but the chassis is very well-balanced, making for an engaging driving experience.

For those who can look past the smaller engine they will be rewarded with an incredibly fast and rewarding-to-drive member of the AMG family.

Note: CarsGuide attended this event as a guest of the manufacturer, with travel, accommodation and meals provided.

Elegance. That's the word that springs to mind when you first clamp eyes on the E400 Cabriolet. While the Coupe version has a crouched-over sportiness about its exterior design, the convertible is all about big and boat-like proportions, especially with the fabric roof opened.

Like nearly all drop-tops, the E400 looks best with the cabin open to the elements, and the side profile especially paints a picture of well-heeled wafting, with only the AMG alloys and body styling hinting at the performance on offer under the bonnet.

Inside, expect perfectly executed modern luxury, with soft leather seats, touchpoints that melt under the fingers and a sprinkling of woodgrain trim. All of which feel like old-world luxury, nicely juxtaposed by the huge twin-screen display that dominates the dash.

The GLC63 is unmistakably an AMG from the moment you first lay eyes on it. That’s thanks to the AMG-specific elements, starting with the grille with vertical strikes and the AMG crest on the bonnet; which is now a signature item for the performance sub-brand.

The GLC63 is also fitted with the Night Package II design kit; this adds a darkened grille and black chrome badging to further enhance its visual appeal.

The AMG-specific alloy wheels and more aggressive stance do mean the GLC63 stands out from the rest of the GLC range, helping it look fast even when it’s standing still.

It's a two-door, four-seat convertible, so practicality isn't at the very top of its list of strengths.

That said, life is peachy for upfront riders, both of whom will travel in spacious luxury. There are two cupholders hidden beneath a woodgrain cover underneath the climate controls - also home to a power outlet - as well as a clever double-hinged central storage bin that can be opened by either the passenger or driver, and which opens to reveal two USB points.

There's room in the doors for bottles, too, and the entertainment system can be controlled via a touchpad controller mounted above the traditional click wheel - although, to be honest, using it is harder and more time consuming than simply pretending it doesn't exist.

Climbing into the back (and we mean climb - there are no rear doors) is made easier by the fact you can fold and slide the front seats automatically by pulling a lever mounted near the headrest. Once there, though, you'll find space is a little tighter, and you feel weirdly cocooned, owing to the huge raised tunnel that runs through the middle of the cabin, and the low roof line.

There are two cupholders that live in the space where the middle seat would normally go, and there's a little bottle-holder cubby to the left of both backseat riders. There are air vents back there, too, but no temperature controls.

The front doors are huge and really very heavy, requiring considerable heft to open them.

The boot space is predictably a little limited, with 385 litres on offer. There's also a little flip-down separator, which shows you how much room the roof will need to come down, reducing boot space to 310 litres. Speaking of which, the soft-top can be lowered in just 20 seconds, and at speeds up to 50km/h.

One practicality quirk, though. The front (and only) doors are huge and really very heavy, requiring considerable heft to open them, especially if you're parked on a slight angle. Honestly, I was reduced to kind of pushing them open with my foot at times.

Inside the GLC63 is clearly a derivative of the rest of the range, with its C-Class-inspired design and layout, but there’s enough AMG-specific elements to ensure it looks and feels special. This starts with the AMG steering wheel, which comes not only with a thick rim wrapped in Alcantara, but also some AMG special dials to adjust the various performance settings for the powertrain, suspension and transmission.

Then there are the AMG-specific seats, which look good and offer good support for the driver and front seat passenger. The rear seats offer decent space for what is a mid-size SUV, with room enough for two adults or teenagers or three smaller kids.

Those in the back aren’t particularly well looked after though, with only rear air-con vents and small door pockets but no USB charging ports or other small item storage.

The boot is 590 litres, down from 620L in the rest of the range, thanks to the addition of the rear-mounted electric motor. There’s also no room for the temporary spare the rest of the GLC range gets and instead you have to make do with a puncture repair kit.

The power and torque figures aren’t the only numbers that have risen sharply, with the GLC63 clearly impacted by a double whammy of inflation and the usual new-car price rise.

The GLC63 now starts at more than $191,814 for the SUV and $198,415 for the Coupe, which represents a nearly $30k increase over the old V8-powered model, which was priced at $164,600 just two years ago. Even for luxury car buyers that’s a big jump, especially when you’re trying to convince people of the merits of the four-cylinder powertrain. 

That also means it's more expensive than all of its key competitors, including the BMW X3 M Competition, Maserati’s Grecale and the outgoing, petrol-powered Porsche Macan GTS.

To help explain some of this price increase Mercedes-Benz Australia has opted for a high level of standard specification for local cars. Standard equipment includes 21-inch alloys, AMG composite braking, a panoramic sliding sunroof, a unique AMG steering wheel, power-adjustable sports seats in Nappa leather, a head-up display, dual-zone climate control, wireless smartphone charging and a Burmester 3D Sound system.

Also included is the AMG Track Pace suite, for those who want to unleash their GLC on the racetrack.

There’s also a limited run, AMG Edition 1 Package available too, for an additional $12,900. On the outside you get Manufaktur graphite grey magno paint, foiling with colour gradation and large AMG logo on the sides, an AMG Aerodynamics Package, unique alloy wheels with Edition 1 and AMG branding, yellow brake calipers and an AMG fuel filler cap in silver chrome with AMG lettering. 

Inside there’s AMG Performance seats, AMG Nappa leather in black with yellow contrasting stitching, AMG illuminated door sills,  carbon-fibre AMG trim highlights, yellow seat belts and a unique AMG Performance steering wheel wrapped in carbon-fibre and microfibre.

It's a fabulous engine, this twin-turbocharged V6 - even if it doesn't feel quite so lively in Cabriolet form as it does in the hardtop equivalents.

The 3.0-litre unit produces 245kW/480Nm, sending it to all four wheels via a nine-speed automatic transmission, linked to the standard 4Matic all-wheel drive system.

This is what lies at the heart of the AMG GLC63’s success or failure. As I mentioned at the beginning, the previous generation’s 4.0-litre twin-turbo V8 has been replaced by an F1-inspired plug-in hybrid powertrain.

But don’t think that means AMG is suddenly focused on efficiency over performance. When AMG says the powertrain is inspired by the brand’s success in Formula 1 racing, what it means is the battery and electric motor provides a significant performance boost to support the internal combustion engine, not just save fuel.

To that end the combination of the turbocharged 2.0-litre four-cylinder petrol engine and the rear-mounted electric motor produces an impressive 500kW and 1020Nm. That’s a massive jump over the 375kW/700Nm made by the outgoing V8.

Mercedes claims 7.4L/100km on the combined cycle (but you can expect to be pushing nine litres in real-world conditions), with emissions pegged at 170g per kilometre of CO2.

The 66-litre tank will only accepts 95RON fuel.

Mercedes makes no secret that the battery is designed for performance, not saving fuel. It only has a 14km EV range but can recharge quickly on the move to provide a power boost when needed.

But despite all that, the GLC63 is actually significantly more fuel efficient than the old V8, using a claimed 7.3L/100km, which is a massive 4.9L/100km improvement over the old model. Although, on our day-long test drive we didn’t manage to come close to that claimed figure and instead saw returns around 11L/100km, albeit after a lot of spirited open-road driving.

Sure, the E400 Cabriolet can drive itself, but we’re equally pleased to note that it’s still a lot more fun handling the steering duties yourself.

And that is mostly due to that fabulous engine; quiet and effortless at city speeds, rorty and enthusiastic at pace, and genuinely angry with the drive setting switched to their most hardcore Sport+ mode.

We’ve already spent time in the sedan version, and while this Cabriolet is heavier (1935kg vs 1820kg) and slightly slower to 100km/h (5.5sec vs 5.2sec) it doesn’t immediately feel it behind the wheel, with a similar and satisfying lurch into the future when you plant your foot.

But hard charging is not what this car is about, and the E 400 is at its peachy best when rolling about the city or the ‘burbs with the top down, and the warm summer air washing through the cabin.

In its normal drive settings, the steering is light but engaged, and the ride on offer from the standard air suspension is outstanding, cosseting the cabin from all but the very worst road imperfections, while the torque from the V6 serves up effortless, unobtrusive acceleration.

With the roof up, Merc’s designers have done a stellar job of hiding the fact this thing is a convertible at all. It’s a solid-feeling cabin with the fabric roof fastened, and the cabin is quiet and free from wind noise.

Anyone who still believes in the adage ‘there’s no replacement for displacement’ hasn’t driven a modern turbocharged and hybridised engine. The GLC63 is a demonstration of the metaphorical and literal power of modern technology, combining an extremely efficient and potent internal combustion engine with an electric motor to make enormous real-world performance.

To be blunt, the GLC63 feels like a rocketship out of corners, launching with a ferocity and relentlessness the old V8 simply can’t match. It shouldn’t come as a surprise, a mid-size SUV with 1020Nm was always going to have plenty of performance, but even so it’s a shock to the system every time you give the GLC63 full throttle. Officially AMG claims it takes just 3.5 seconds to run 0-100km/h and has an electronically limited top speed of 275km/h - mighty impressive figures for a five-seat mid-size SUV.

To help get all that torque to the road, AMG deploys torque distribution technology that allows for it to be split an even 50/50 front/rear all the way to 100 per cent to the rear tyres.

Other technologies deployed to enhance its handling include AMG Ride Control suspension with adaptive damping and rear-axle steering. There’s also eight AMG Dynamic Select driving modes and four AMG Dynamics settings (Basic, Advanced, Pro and Master), so it’s a complex vehicle that is designed for the enthusiast.

While it’s easy to drive around town, once you get out on the open road you can really get a sense of the GLC63’s performance potential. Beyond just its powertrain the suspension offers good body control and the rear-axle steering helps it feel agile and responsive. 

It’s not perfect though. At times the complexity of the system does lead to some hesitation when you put your foot down. It certainly lacks the linear power delivery of the old V8 and makes for a slightly trickier driving experience at times.

As for the sound, which is one of the biggest elements missing from the V8, Mercedes has added AMG Real Performance Sound, which features a pressure sensor in the exhaust that picks up on the engine note and plays it through the speaker system. It certainly helps make for a louder, more noticeable engine noise, but it still sounds more like an A45 than the previous GLC63 and for many would-be buyers, that’s a major turn-off.

The GLC63 comes standard with a comprehensive suite of safety features including 'Distronic' (Mercedes’ name for adaptive cruise control), 'Active Lane Keeping Assist', 'Blind Spot Assist', 'Traffic Light Assist' and 'Adaptive Highbeam Assist'. It also includes Mercedes’ 'Pre-Safe' accident anticipation system - which pre-tensions the seat belts and will even play a white noise to protect your ears if it senses a crash is imminent.

A parking system that includes a 360-degree camera and active parking assist is also included.

The GLC range was awarded a five-star ANCAP rating in 2022, which pre-dates the latest testing protocols, so doesn’t provide a like-to-like comparison for vehicles tested after that date.

Expect the usual three-year, unlimited-kilometre warranty, with service intervals pegged at 12 months or 25,000km. Mercedes' capped-price servicing scheme limits maintenance costs to $2280 for the first three years of ownership.

The GLC63 is covered by Mercedes Australia’s usual five-year/unlimited kilometres warranty.

As for maintenance, Mercedes offers service plans, spanning three to five years. Three years will cost you $5025, $6455 for four years and five years is priced from $7180. Servicing intervals are 12 months or 20,000km, whichever comes first.