BMW 4 Series vs Mercedes-Benz AMG GT

What's the difference?

The BMW M440i xDrive Gran Coupe manages to combine sleek design with a fun-to-drive personality and surprising practicality. It’s a rapid premium, four-door, five-seater offering extra flair, and in this part of the market, good value. But more than anything else it’s got a cracking in-line six under the bonnet.

The GT63 4Matic+ is a breathtaking example of everything that Mercedes-Benz and AMG are.

Ferociously fast, incredibly agile and superbly sophisticated, it should be on anybody’s shortlist, if that also includes a Porsche, Aston Martin, Maserati or even a Lamborghini. And it’s definitely much more than yesterday’s SLC ever was – for similar money in today’s terms, as it turns out.

But, around Tasmania’s glorious roads at least, the Mercedes-AMG lacks the ride comfort and road noise isolation to be a fully-rounded-out GT, and that’s a disappointment for a brand with such formidable history in making such cars.

So, how does this four-door 4 Series differ from a four-door 3 Series? The answer is as plain as the nose on this car’s face.

BMW’s head of design, Adrian van Hooydonk, has been expanding the brand’s signature ‘kidney grille’ in every conceivable direction, and this is the much talked about interpretation adorning all 4 Series models (petrol, hybrid and electric) as well as the M3 sedan.

The new Gran Coupe is longer, wider, and taller than the outgoing model, and the track is broader, front and rear. The wheelbase has also been extended, now a whole 5.0mm longer than the 3 Series.

The DRLs and headlight main beams are LED with laser high beams, immense gills square up the edges of the front clip, while a vent and the strake attached to it stand the car apart. Plus, of course, the doors are frameless. 

One niggle, though. I’m not in love with the slender door handles. It’s hard to get a good grip on them, especially in the wet. 

Standard 19-inch alloy rims are shod with Pirelli P Zero rubber 245/40 fr / 255/40 rr), the roofline slopes distinctly towards the rear, a lip spoiler on the trailing edge of the tailgate is classic BMW, darkened LED tail-lights wrap around the rear corner, and a diffuser-type panel is flanked by large exhaust apertures.

Our car’s ‘Aventurine Red’ finish is a $3850 option, but to my eyes anyway it looks superb.

Exterior trim including the grille frame, front air intake inserts, mirror upper housing, model designation badges, and tailpipe are finished in ‘Cerium Grey’, which I reckon 99.9 per cent of people will see as black. 

The interior will be familiar territory for any current BMW owner, the 12.3-inch digital instrument screen sitting in a compact, hooded binnacle, and partnering with a 10.25-inch multimedia display standing proud of the dash above the broad centre stack. 

The seats are trimmed in top-shelf leather with blue contrast stitching, plus the grippy sports wheel is also wrapped in genuine hide.

BMW calls the finish on the main buttons and controls ‘Galvanic’ which translates to a slick silver metallic look and feel. Configurable ambient interior lighting is a nice touch, and the broad console enhances the driver-focused feel, with a sprinkling of carbon-fibre around the centre console and dash lifting the sense of occasion.

Overall, the interior feels clean and classy with an obvious attention to detail.  

This is still clearly a Mercedes AMG GT coupe, like the 2014 C190 original, but a ground-up redesign sees it subtly yet significantly altered.

Some 270kg heavier than before, the larger-in-every-dimension body combines aluminium, steel, magnesium and fibre composite materials for improved rigidity and a lower centre of gravity. Length (4729mm) and wheelbase (2700mm) have been stretched by 177mm and 70mm respectively. Width (1984mm) and height (1352mm) are also up.

The nose treatment is similar to before, especially with the bulgy bonnet and signature vertical slatted grille fitted. These, combined with the LED digital headlight shape effect, is reminiscent of, but far-better executed than, the goofy-looking MG5’s face.

Underneath, it's an all-new platform shared with the SL, with the rear transaxle of the old car replaced by a permanent AWD system, leading from 46:54 front/rear weight distribution to 50:50 as a result.

That aggressive, exaggerated cab-backward/ultra-long bonnet silhouette that visually connected it with the SLS gives way to more-conventional and practical coupe proportions that is striking if not especially original, since they do look quite 911-esque. Along with the longer wheelbase and wider tracks, the result allows for two small rear seats to be fitted, while liftback cargo access remains.

Similarly, in the name of way-more usable interior packaging, Mercedes-AMG says it pushed the driving position nearly 180mm forward compared to the previous GT. Let’s see what that all looks like inside.

At close to 4.8m long the 4 Series Gran Coupe is a sizeable machine. Up front, the feeling is airy and comfortable, and the rear is surprisingly spacious, especially in light of the car's sloping roofline.

At 183cm I have to fold myself tightly to fit under the low roof, but once inside I have enough room to sit behind the driver’s seat set for my position with more than enough legroom and adequate headroom. Put three full-size adults across the back row, though, and there will be breathing difficulties.

Kids will be fine, however, and individual vents with adjustable temp in the rear was a big plus during a particularly hot test week.

For storage there are generous door bins in the front with room for large bottles, a decent glove box, dual cupholders in the centre console, a reasonable lidded bin (which doubles as a centre armrest), and the wireless device charging bay (forward of the gearshift) makes a handy oddments space when not in use.

In the rear, again the doors feature pockets with room for (medium-size) bottles, there’s a fold down centre armrest with two cupholders, but thanks to the one-piece shells on our test car’s optional M Sport front seats there are no map pockets.

Power and connectivity runs to a USB-A socket and a 12V outlet in the front centre console, as well a USB-C port in the front storage bin, a pair of USB-Cs in the rear, and a 12V outlet in the boot.

Speaking of which, lift the tailgate and with the rear seat upright we were able to fit all three of our suitcases or the beefy CarsGuide pram into the healthy 470-litre (VDA) boot space.

Lower the 40/20/40 split-folding rear seat down and 1290 litres of volume is at your disposal. Plus there are handy bag hooks and tie-down anchors to help secure loose loads.

You can also tow a braked trailer up to 1.8 tonnes (750kg unbraked), but don’t bother looking for a spare of any description, a repair/inflator kit is your only option.

The first impression inside is that of space, despite the falling roofline and coupe-like upsweep of the side windows and you look back. While, again, similar to a 911s, a kink at the door gives the GT a unique character.

Even larger people will appreciate the generous amounts of room up front, with space to stretch, sat in sumptuously comfy bucket seats. Note that the standard ones are better than the racier but firmer Sports versions.

The driving position is perfect, ahead of a dashboard that is very typical modern Mercedes in appearance and layout.

To that end, the tablet-style integrated touchscreen (11.9 inches) is clear, fast and intuitive once time is taken to learn it. And points are also won for the multi-configurable electronic instrumentation, that allows for a variety of screens, including track, classic and minimalist views.

The trademark turbine air vents, the quite beautiful material and trim finishes and just the general solid feel are further typical contemporary Mercedes cabin treatments, as are the excellent ventilation and ample storage options.

And while rear vision isn't great, that's what cameras are for. It's all pretty much on brand.

It is a shame, given how elevated the Mercedes-AMG engineering is underneath, that the GT’s interior look and ambience is so similar to those of a (albeit higher-spec) C-Class or GLE. It's simply not as special as some of the company’s previous sports cars.

More annoyingly, the ride is too firm and bumpy for a GT, and this has the unhappy effect of provoking random rattly trim sounds within the cabin. It’s a bit like scrunched-up cellophane. In a $420K (as tested) Merc, that’s very disappointing, especially as it can be heard over the copious amount of road and tyre noise droning through, particularly on coarser bitumen surfaces.

Further back, the rear seat is strictly two-plus-two, and nobody over 150cm tall is recommended to travel there by Mercedes itself. That sloping roofline is the culprit. That said, brief trips with a bowed head are possible, as the fixed cushions and split-folding backrests are actually surprisingly comfy. But only for short journeys. Kids should love it though, and the second row does open up the GT’s usefulness enormously.

As does a near-doubling of the AMG’s cargo capacity, jumping 146 litres to 321L with backrests erect, to a whopping 675L (+325L) in two-seater mode. The flat floor is accessed via a large electrically-operated liftback door, offering quite a large aperture for easy loading/unloading.

Having no spare wheel helps here, with a tyre inflation kit included in lieu of that.

Meanwhile, at the front, under the bonnet, things have definitely changed for the better as well.

Starting from $370,400 (all prices are before on-road costs), the Mercedes-AMG GT63 4Matic+ is priced and positioned as something of an eagle amongst some pretty delectable doves, given its combination of four seats, 430kW of power, 800Nm of torque and four-wheel drive.

No rival equivalents can match the Mercedes on paper. The 398kW/610Nm 911 Carrera 4 GTS T-Hybrid offers less power but starts from $400,000-plus. The 410kW/650Nm GranTurismo Trofeo begins at $450K, the 500kW/800Nm DB12 from $455K and the 404kW/470Nm Continental GT from $460K.

Only the 460kW/750Nm BMW M8 Competition comes closest to the Mercedes-AMG, from $380K.

Side note, today’s GT is only slightly more expensive than what the 450SLC was nearly half a century ago when adjusted for inflation.

And, just like with that classic old Benz, it shares much with the brand’s legendary SL convertible stablemate – including, in this case, standard all-wheel drive and active rear-axle steering… aka 4WS to select third and fourth-generation Honda Prelude owners out there.

What else does $400K-plus buy you? As you’d expect, the GT63 4Matic+ comes choc-full of standard equipment, much of it typical of the luxury coupe breed, with leather-covered and electrically operated everything.

How about a front-axle lift system with GPS-enabled memory that automatically raises the GT’s nose to help clear bumps and then remembers to do so next time?

There are climate-controlled AMG sports seats with inflatable bolstering and massaging functionality, a fixed glass roof, a head-up display, augmented-reality satellite navigation, 360-degree surround views, performance telemetry data as part of an extensive multimedia system, an 11.9-inch portrait touchscreen, 11-speaker Burmester audio, a handsfree-powered tailgate, 21-inch alloys and cutting-edge driver-assist safety tech. More on that in the Safety section below.

Then there are the myriad option packs, bumping the GT63’s price up towards $500,000. These include a $2.7K seat trim package; a $10K AMG Night Package that adds darker trim treatments (often where chrome was); an aerodynamics package with fixed spoiler replacing the standard active spoiler; a $2.6K AMG Performance Seat package; a $13K Carbon Fibre package and $13.2K Ceramic Brakes.

Now, while the new GT does ditch the previous model’s unique rear transaxle spaceframe pioneered by the gull-winged SLS of the early 2010s, the resulting longer wheelbase and shorter overhangs do provide less outlandish and more practical design.

Let’s check that out in more detail. 

Under the bonnet is BMW’s (B58) all-alloy 3.0-litre twin-scroll turbo intercooled, in-line six-cylinder engine, driving all four wheels via an eight-speed automatic transmission and electronically controlled clutch pack, as well as an electronic limited-slip differential at the rear.

It features high-pressure direct-injection and BMW’s ‘Valvetronic’ system managing air flow to the intake side, to produce 285kW at a relatively high 5800-6500rpm. But the big punch is 500Nm of peak torque from just 1900rpm all the way to 5000rpm.

The M440i is also a mild-hybrid with a 48-volt starter motor-generator and supplementary battery able to give an 8.0kW kick at low engine speeds.

There’s a plaque signifying which engineer “handcrafted” the GT’s engine – in this case, the famous M177 in 3982cc, 4.0-litre twin-turbo intercooled V8 petrol guise.

Delivering 430kW of power at 6500rpm and 800Nm of torque from 2500-4500rpm, it sends drive to all four wheels via a nine-speed multi-clutch transmission (dubbed MCT in AMG-speak), catapulting the GT63 4Matic+ from 0-100km/h in just 3.2 seconds, on the way to a top speed of 315km/h.

How does it do that?

With AWD, the GT is now nearly 15 per cent heavier than before, but it still manages a punchy 218kW/tonne. Active aerodynamics over, inside and under a more-rigid body structure also helps.

The AMG 4Matic+ AWD system goes from 50/50 front/rear, to 100 per cent rear, variable torque distribution according to conditions and settings, and backed up by an electronic limited-slip differential. Among the many driving settings are Race Start, Drift Mode and good-old Comfort, if it all becomes too much.

Also keeping all that performance in check is a high-performance composite brake setup with improved cooling for faster responses.

Interlinked active roll bars improve body control, the five-link independent suspension features adaptive dampers for a softer ride.

And, as for that 4WS tech, the rear wheels steer opposite to the fronts at up to 100km/h (by some 2.5 degrees) for tighter and tidier handling, or 0.7 degrees in the same direction above 100, for greater stability and road-holding.

Its effect on the way this near-two-tonne coupe zigs and zags around corners is something you need to experience to really appreciate.

BMW’s official fuel economy figure for the M440i xDrive Gran Coupe, on the ADR 81/02 - urban, extra-urban cycle, is 8.2L/100km, the 3.0-litre turbo six-cylinder emitting 187g/km of C02 in the process.

Stop/start is standard, and we saw an average of 11.1L/100km over city, B-road and freeway running during a week with the car.

With the 59-litre tank brimmed (with minimum 95RON premium unleaded) that real-world test number translates to a range of around 530km.  

Actually, the GT’s economy isn’t horrendous considering how fast it can go.

Even blasting a few times around beckoning country roads, we managed an indicated 13.0L/100km, which is an improvement on what Mercedes-AMG says the GT averages the 14.6L/100km average that Mercedes-AMG officially states.

That translates to a carbon dioxide emissions rating of 334g/km.

Using 98 RON premium unleaded petrol, an average of just under 480km between refills of the 70L tank is possible. The urban run sees consumption rocket to 21.8L/100km (for just 321km of range), or 10.4 out on the highway run, meaning that over 670km is possible should you decide to drive in a docile manner.

BMW says the M440i xDrive Gran Coupe will accelerate from 0-100km/h in 4.7sec, and I reckon the threshold for a properly quick car is sub-five seconds.

The 3.0-litre turbo six develops its peak power of 285kW between a relatively lofty 5800-6500rpm, but the big number is a solid 500Nm punch of pulling power delivered between 1900-5000rpm.

Squeeze the throttle pedal pretty much anywhere in the rev range and the response is glorious. Rapid acceleration accompanied by raucous engine noise and rorty exhaust note (albeit with some synthetic support). Various pops and bangs in the Sport settings add extra entertainment.. 

The eight-speed auto gets some electric support from the mild-hybrid system to fill the torque gap on up shifts, and the result is a conventional torque-converter transmission that behaves like a dual-clutch.

Shifts are seamless in general driving, and satisfyingly quick in a more aggressive mode, the wheel-mounted paddles dialing up the fun in manual changes. 

Suspension is double wishbone front and multi-link rear with the standard ‘Adaptive M Suspension’ built around an adaptive damper set-up.

The change between the ‘Comfort’ setting to the ‘Sport’ or ‘Sport+’ calibration is close to instant and makes a discernible difference, especially in terms of ride comfort.

I found the best ‘Individual Sport’ arrangement to be damping in Comfort, with the steering engine and transmission in Sport. The car flows so beautifully through corners with urgent response from the powertrain.

By all means dial up the suspension if you’re having a real crack, but the car feels superbly balanced, stable and predictable in Comfort (front to rear weight distribution is 50:50).

The electrically-assisted variable-ratio steering is nicely weighted with good road feel, and the grippy sports steering wheel is a nice point of contact.

The xDrive AWD system’s default setting is rear-biased, although it will push most of the drive forward when required. But the RWD feel is unmistakable. 

The M440i weighs in at around 1.9 tonnes but feels lighter and more nimble than that figure would typically indicate.  

A standard electronically-controlled M Sport limited-slip differential puts the power down confidently. I have a favourite LSD test corner on my regular evaluation drive, a sharply twisting and rising left-hander.

Rolling into it in a low gear before planting the throttle mid-corner, the car simply hunkers down without a hint of fuss (or traction loss) as it rockets out the other side.

Optional M Sport front seats ($2000) provide comfort and firm location in equal measure and in terms of ergonomics BMW knows how to focus on the driver and set-up an efficient environment. Key controls are perfectly positioned and simple to operate.

I have an issue with the ‘Lane Departure Warning’ function, however, which is too quick to intervene and overly intrusive when it does so. I turned the ‘Steering Intervention’ function off. You can dial down steering wheel vibration warnings, too.

The standard M Sport brakes feature big vented rotors front and rear, with fixed four-piston front calipers doing the bulk of the work. They’re strong but don’t bite or release too aggressively. It’s easy to grease in a smooth application. 

Nobody will drive the GT63 4Matic+ and think, ‘Oh, this is OK’, because its breadth of performance is phenomenal.

No matter which mode you're in, from Comfort through to track-tuned Race, the Mercedes-AMG blends forceful pace and commanding control without ever breaking a sweat.

Flex your right foot and the two-tonne coupe bounds into action like a giant on a mission, striding past posted speed limit signs in nanoseconds and way, way faster than the law will stand if diligence isn’t exercised.

And there’s no point relying on seat-of-your-pants sensations, either, because the chassis below embraces the road with an almost zealous devotion. Which is astounding, given how agile the four-wheel steering-enhanced handling is.

The 63’s super power is exactly that – it dulls your sense of speed. One tester admitted to exceeding 150km/h before noticing. An odd confession considering the sonic boombox that is the bi-turbo V8’s howl.

But jailbait performance is not even the 63’s most lingering joy. That would be its steering perfection, that delivers that rare trifecta of keenness, crispness and communication. The wheel feels eager and alive in your hands, even when powering between tight turns, backed up by sensational grip and control. How can a two-tonne GT handle so sharply?

Warm, dry roads were the order of the day, so we can’t tell you how the 4Matic+ permanent AWD system deals with wet or slippery surfaces, but the slick multi-clutch transmission, seamless torque-vectoring tech and sticky tyres more than cope with the 63’s formidable outputs.

So, that's the gushing part out the way, then.

Despite the adaptive dampers, rigid architecture and exquisitely sophisticated suspension, the ride is simply too stiff in Comfort mode, and downright jittery on some of the Tasmanian roads we tested on, for the 63 to be considered a true luxury grand tourer. It just isn't comfortable, luxurious or supple enough.

Plus, grippy as they are, the 21-inch wheels transmit too much road and tyre noise through to the cabin, meaning that the GT isn't as quiet as you'd hope. Add the aforementioned trim squeaks, and the expected cocooned silence isn’t always there.

The upshot is that the 63 possesses more of a sports car character than a luxury GT character. Great news if you're a 911 type buyer and are seeking a high-performance 2+2 alternative, but a disappointment if comfort and refinement are priorities.

Still, it is impossible not to be deeply moved by this Mercedes-AMG.

While the GT doesn’t score an ANCAP rating – probably because it’s too expensive to crash test – we’d wager that it would be above-average, given Benz’s track record as a pioneer in this field.

That’d due to the scores of active, passive and driver-assist safety features fitted, from multi-faceted autonomous emergency braking (AEB) and lane-support systems to Mercedes’ PRE-SAFE tech that anticipates a crash and then prepares the car for impact.

More specifically, the GT includes Active Lane Change/Keep Assist, adaptive high beam as part of its megapixel LED set-up, adaptive cruise control, Cross-Traffic Assist, Evasive manoeuvre support, an emergency services call-out system, 360-degree camera views, pedestrian protection bonnet and eight airbags.

In other Mercedes products of today, AEB operating parameters are 7-80km/h for vulnerable road users like pedestrians and cyclists, and from 7-250km/h for vehicle-to-vehicle, while the lane-keep support systems operate between 60-200km/h.

Finally, there are ISOFIX child-seat anchorages in the front passenger seat and two in the rear seats.

The M440i Gran Coupe is covered by BMW’s three-year/unlimited km warranty (including paintwork), as well as 12-year/unlimited km anti-corrosion (perforation) cover. 

That’s off the premium market pace now with Genesis, Jaguar, and Mercedes-Benz at five years/unlimited km and Lexus set to join them from January 1st, 2022. 

That said, roadside assistance is provided for the duration of the main warranty, but it’s worth noting “rattles and squeaks” are only covered for one year.

Service is condition-based, the car telling you when maintenance is required, and a range of service packages are available. The basic plan covering a 4 Series for five years/80,000km comes in at $1750. 

What’s the GT like to own?

Mercedes-Benz offers a five-year/unlimited km warranty, with five years of roadside assistance. This is average for most mainstream and luxury brands, but superior to most sports-car makers like Porsche and Lamborghini.

Intervals are every 12 months or 20,000km, and while no capped-priced servicing is offered on the GT, pre-paid three-, four- or five-year service plans are available, ranging from $5165, $7700 and $8665 respectively.

Big performance demands big maintenance bills, it seems.