Mercedes-Benz GT vs BMW 6 Series

What's the difference?

The Mercedes-AMG GT Black Series is a rare beast; in the sense that it’s both unattainable and that it makes you feel like a superhero behind the wheel.

There is more performance on offer than most can hope of using, but the best thing about Mercedes’ latest supercar is its approachability.

In my experience, the more expensive a car gets, the more stressful driving them becomes, but the Mercedes-AMG GT Black Series does something I didn’t think was possible, and turns a near-$1 million supercar into something fun.

This isn't a car for everyone's tastes, but if you fit in to the buyer group that just doesn't really know what they want in a luxury car, it could be the perfect fit for your family. The 6 Series GT is a practical large prestige car, albeit one that will likely find very few buyers.

Most high-performance brands have their hardcore, track-focused models, from the Porsche 911 GT2 RS to the McLaren 765LT and the Ferrari 488 Pista.

For Mercedes-Benz, it’s the Black Series, a badge which could be found in the past on the SLK, CLK, SL-Class, C-Class, but for 2021 it’s now found on the back of the GT supercar.

To differentiate it from the rest of the ‘standard’ Mercedes-AMG GT range, a slew of racecar-like components are added, such as a fixed rear wing (with deployable insert), vented front fenders, extended front splitter and fixed-back seats.

In fact, so different is the Black Series, that the only panel that carries over from the GT is the roof, which is a carbon-fibre component to keep weight down.

Other carbon-fibre bits include the front fenders, front and rear bumpers, and rear hatch.

The most in-your-face addition might be the deeply vented bonnet, designed to evacuate hot air from the engine bay, while the hero 'Magma Beam' orange colour that juxtaposes all the exposed carbon-fibre panels is a real attention grabber.

From the outside, the Mercedes-AMG GT Black Series is bold, brash and in-your-face, but that’s exactly what a race car should be – in my opinion, at least.

I absolutely love how the Black Series looks like a Need for Speed or Forza Horizon video game car brought to life, and will turn heads anywhere you go.

Inside, the Black Series is clad in soft-touch 'Dinamica' and orange contrast stitching across many of the touchpoints such as dashboard, steering wheel and door cards.

And with fixed-back bucket seats, a racing harness and a roll cage, you’d be forgiven for thinking the AMG GT Black Series is all about function over form, but there are small touches to make it easier to live with on the road.

The multimedia touchpad controller falls easily in hand, while the shifter is flanked by an array of light-up buttons to adjust settings like adaptive suspension, exhaust note and rear spoiler angle.

Overall, the Black Series’ cabin is well-laid out like a standard AMG GT, with some nice flourishes to stand it apart.

There is no denying the 6 Series GT looks better than the old 5 Series GT. It isn't as frumpy, it looks more sporty, and to me it appears to have grown into its identity with more conviction than its predecessor.

That said, I don't necessarily like the look very much - it's a bit like a BMW X6 that has been rounded off a little and lowered down substantially. But I can appreciate some of the finer design aesthetics that it offers up: the frameless windows are a nice touch, and the swooping roofline looks smoother than a duck's back.

Other things like the active grille shutters and the air breathers ahead of the front doors are nice functional touches, and to my eye it lives up to BMW's hope of it looking "smooth but muscular". You can get the 630i with either the M Sport package, like you see here, or the more sedate Luxury Line, which is, well, more luxurious looking.

The M Sport styling and equipment package you see in the images here - with M aero kit and 19-inch wheels (ours had been upgraded to optional 20s) - help out with the athletic look of this very big vehicle.

It's huge in fact. The length of the 630i is 5091mm long, it measures 1902mm wide and sits at 1538mm tall, with a lengthy 3070mm wheelbase.

All that equates to a lot of room in the cabin, and what a sumptuous and delightful place it is to be - leather, wood and plush finishes abound.

As a two-seat coupe, the AMG GT Black Series isn’t the most practical of cars, but then again, it isn’t trying to be.

The cabin is big enough to accommodate six-foot tall (183cm) passengers like myself, though the fixed-back seats are designed to be form-fitting even for slender frames.

Storage options inside include two cupholders and a shallow underarm storage cubby, and that’s about it.

Unlike the standard GT, the Black Series’ doors forgo the small storage pocket – likely to keep weight down.

Opening the boot reveals enough space for a set of golf clubs or a few weekend bags, but not much else.

Mercedes does not list the volume available in the Black Series, but with the inclusion of a rollcage and special reinforcement components to help transfer the downforce of the rear wing to the chassis, it’s safe to assume it is less than the 176 litres offered in the AMG GT.

Now, I said before that this is a bit like an X6, but it has heaps better interior space than that SUV.

As soon as you slide into the driver's seat, you feel like your inside a large car. The cabin space is plentiful, and there's an abundance of storage on offer, too: there's a split-lid armrest between the seats, a pair of cupholders, a phone storage nook with wireless charging, and big door pockets with bottle holsters.

In the back you have access to door pockets, a flip-down armrest with cupholders (that middle part of the seat can fold down completely to allow storage of longer items), and there's excellent room on offer. How many seats in the BMW 6 Series GT? Five - like, five full-size seats.

Because the roofline doesn't rake as sharply as a four-door 'coupe', headroom is excellent for adults (even of the 183cm variety, like myself), and legroom and toe room are equally very good. This is bigger in the back than a 5 Series, but maybe not as plush as a 7 Series… so I guess it makes sense numerically for its nomenclature.

Of course you get climate control in the front (and in the rear if you option it), and the materials are excellent. The media screen is tablet-style, proudly displaying 10.25 inches of high-def real estate that is both touch-capacitive and controllable by way of the central rotary controller with touchpad. And get this - you can even use gestures to control certain elements like volume, swiping and changing tracks… but you have to option that.

The fully digital instrument display is bordered by a set of incomplete dial rings, which is just odd. BMW, back yourself - your buyers can handle just having a digital screen in front of them, particularly when it's as good as this one.

This grandiose hatchback's boot is commodious - with the back seats in place it has a huge 610 litres of cargo capacity, which extends to 1800L with the 40/20/40 seats folded down using the quick release levers in the boot area.

There is no spare wheel (the BMW range is fitted with run-flat tyres) but it does have a secondary hidden storage area under the boot floor for hiding items or stowing wet gear, bathers/swimmers or muddy clothes.

For context, the X6 has 580L seats up, 1525L seats down.

The BMW 6 Series Gran Turismo range starts off with the model tested here, the 630i. It has a list price of $123,500 before on-road costs - and that's whether you buy the M Sport Line or the Luxury Line.

That's quite a lot of money. And while it has a lot of equipment to help justify the cost, the smarter dollars will probably find their way to a more affordable 5 Series.

Standard gear in this spec includes adaptive air suspension with multiple drive modes, a colour head-up display, semi-autonomous parking, adaptive cruise control with steering assistance, auto high-beam LED headlights with LED daytime running lights, DAB+ digital radio, a 16-speaker harman/kardon sound system, a 12.3-inch driver information screen and a 10.25-inch media display with sat nav, Bluetooth and 'BMW ConnectedDrive' online services.

Hey, you even get a panoramic sunroof as standard! Plus there are things like an active rear spoiler, two USB ports and four 12-volt outlets, leather trim, heated front electric seats, electric steering wheel adjustment, keyless entry, push-button start, and an automatic boot.

It also comes loaded with active safety assistance functions - we'll get to that in the safety section below.

Things it's missing at this price point? Well, heated seats are an option, but bundled nicely into the 'Comfort Package' ($3000) which was fitted to our car. The pack includes heated seats front and rear, quad-zone climate control, electric sunblinds for the rear side windows, and electric seat back adjustment. Oh, and BMW continues to gouge consumers $623 for Apple CarPlay (which seemingly didn't work in our car).

The only other 6 Series GT model available is the 640i xDrive, which is again available with the choice of M Sport or Luxury body styling. It's also pretty exxy, with a list price of $148,900, but gets a more performance-focused drivetrain, as well as extra equipment: essentially the Comfort package, plus vented front seats, interior fragrance (eight options), memory settings for the front seats, 20-inch wheels and metallic paint.

Plus the 640i has Sport+ settings - it's probably the wrong car for those - and 'Integral Active Steering' to couple with the all-wheel drive system.

Powering the GT Black Series is AMG’s ubiquitous 4.0-litre twin-turbo-petrol V8 engine, with a few modifications.

For starters, a flat-plane crank is used for the V8 for improved throttle response, less weight and different firing order that makes it more free revving than the standard engine.

In fact, so different is the engine that Mercedes-AMG has given the Black Series’ powerplant its own internal code, with only three technicians in Affalterbach qualified to put it together.

The result is peak power of 537kW available from 6700-6900rpm, while maximum torque reaches 800Nm, on tap from 2000-6000rpm.

For those keeping track, that’s 107kW/100Nm more than the GT R.

Sending drive exclusively to the rear wheels via a seven-speed dual-clutch automatic transmission, the AMG GT Black Series will accelerate from 0-100km/h in just 3.2 seconds and top out at 325km/h.

Under the bonnet of the 630i is a 2.0-litre four-cylinder turbocharged petrol engine, which produces 190kW of power (at 6500rpm) and 400Nm of torque (from 1550-4400rpm). It uses an eight-speed automatic transmission, and is rear-wheel drive.

That may not seem a lot considering the size of this machine, but consider that some of the steamiest four-cylinder hot hatches have nearly the same outputs, and you realise this engine offers up a far-from slouched approach to propulsion.

The 640i xDrive has a 3.0-litre six-cylinder turbocharged engine with 250kW of power and 450Nm of torque. It gets the same eight-speed auto, but as the xDrive naming indicates, it's all-wheel drive.

But this is the one you'd prefer if you want to hit highway speed in a hurry - the 0-100km/h claim is 5.3 seconds, where the 630i takes a full second longer (6.3sec) according to the company.

Officially, the GT Black Series will consume 13.2 litres per 100km, making it thirstier than the GT R that returns 11.4L/100km.

The GT Black Series will require 98RON petrol and this, coupled with the high consumption average, will mean a big bill at the bowser.

However, as such a focused performance machine, fuel economy in the Mercedes-AMG GT Black Series is less of an important point than something like a charismatic and dynamic engine.

BMW claims fuel use of 7.0 litres per 100 kilometres, and you'll need to use 95RON premium unleaded when you fill up.

On my trip with the car, I saw about 9.0L/100km across mostly high-speed driving - some freeway, some highway, some country back road touring, and quite a bit of corners and city stuff thrown in as well. I think that's pretty respectable.

What wasn't so great was the lack of premium fuel in some of the 'away from civilisation' places on my route home. Keep that in mind if planning your own GT long-distance cruise.

We’ve driven some very fast cars before, so make no mistake when we say the AMG GT Black Series is seriously quick.

The right pedal might as well be warp drive on the, Starship Enterprise, because as soon as you floor the throttle, you’re pinned to the back of the race seat and the only reprise comes from lifting off.

Aside from the immense speed, what is – surprisingly – noticeable is the noise, or lack of it.

The flat-plane crank V8’s different firing order means it doesn’t have the same burbly notes as the standard AMG GT, it’s a racier tone. That’s not a bad thing, mind you, just a different note.

And while the flat-plane crank V8 changes the exhaust note, it also makes the engine freer revving and lively.

With 537kW/800Nm on tap, you sort of have to trust the suspension and aerodynamics will do their thing to keep the AMG GT Black Series on the track, and it’s here where I think Mercedes-AMG has pulled off some sort of magic.

The combination of adaptive dampers, active aero, beefed-up anti-roll bars and a unique Michelin Pilotsport Cup 2 R tyre (featuring a silhouette of the Black Series laser etched into the sidewall) results in a terrifyingly capable vehicle at Phillip Island.

I am the first to admit that I am no Lewis Hamilton behind the wheel, I often get on the throttle too early, I can never nail a double-apex corner and my heel-toe-technique could use more work, but behind the wheel of the GT Black Series, I felt like Ayrton Senna’s spirit had taken the wheel on my behalf.

Cornering in the Black Series felt like nothing else, and regardless of what the speedo was saying, the nose of the ferocious GT flagship would just point wherever I wanted it to go.

Luckily the braking system is also up to task – thanks to carbon ceramic units fitted as standard, as well as unique pads and discs.

The brakes bite almost immediately, giving you the confidence to hit the stop pedal at the last moment before tipping into a corner.

I think the biggest compliment I can pay to the Mercedes-AMG GT Black Series is that it increases that narrow band of fun you can have in a supercar.

Sure, a driver with more skill could pilot the AMG GT Black Series with more grace, and finesse it around the corners a little quicker, but the approachability of the performance on offer is amazing.

Nothing feels intimidating, nothing feels unapproachable. The GT Black Series is so communicative that it gives drivers the confidence to feel like a hero around a race track.

If there is any criticism of the car, it’s that its limits are so high they are hard to explore, even on a circuit like Phillip Island, but maybe that takes more skill than I have, or more than just a handful of laps behind the wheel.

Of particular note, too, is that the engine of the Mercedes-AMG GT Black Series is found in the front.

There’s a reason why some exotic supercars will opt for the mid- or rear-engine layout, but Mercedes has managed to craft a front-engine, rear-drive machine that will keep up with the best the world has to offer.

I'll put this out there - if you like to drive, there are BMW models for less than this one that will put a much bigger smile on your face. Like, a 440i Gran Coupe, or even just a 330i sedan…

But if you're in BMW's target market - that being older executive buyers who want space and luxury as a priority over thrills at the wheel, you could do a lot worse.

That's because the 6 Series GT lopes along the highway without fuss - the engine easily coping with the demands of overtaking moves, the adjustable drive modes allowing a light steering and wafting suspension feel to wile away the kilometres.

There are 'Comfort' and 'Comfort Plus' modes, but the latter is a bit too spongy and can be boaty feeling. The Comfort setting is made for the highway.

It is actually pretty agile for its dimensions.

If you decide to deviate from the straight sections, you'll be able to explore a little bit of dynamic range, especially when you dial up the 'Sport' mode, which changes the damper settings, steering weight, throttle and transmission response, and even the digital dials in front of the driver to a more aggressive look.

Our car had the 'Integral Active Steering' setting, which is a variable ratio steering system that includes rear steering - that essentially helps make is more turnable in corners at highway speed, and easier to park at lower speeds. It's difficult to say whether the assistance is excellent or not short of driving a car without the tech, but to this tester it was hard to hide the size and weight (1835kg kerb weight) of the vehicle.

That isn't to say it's clumsy or lumbering - it is actually pretty agile for its dimensions, though it makes a lot more sense on long drives and coastal cruises than it does in the narrow and twisty alpine roads of the Snowy Mountains Highway that I tested it on.

There's good grip from the tyres, and strong response from the powertrain - but if it were my money, and I had to have a 6 Series for whatever reason, I'd be looking towards the 640i model, which has a thumping six-cylinder with 250kW/450Nm - certainly an engine that would be more at home in this car. Plus that model comes with AWD.

The BMW 6 Series GT range has a five-star Euro NCAP crash test score based on 2017 testing, but it hasn't been scored by ANCAP.

There's the usual array of airbags - dual front, front side, full-length curtain and driver's knee airbags are included, plus parking sensors all around, and heaps of safety tech including the 'Driving Assistant Plus' package with lane departure warning and lane keeping assist, forward collision warning, auto emergency braking (AEB) front and rear, blind-spot monitoring and rear cross-traffic alert, and adaptive cruise control with stop and go.

That's all great stuff, and so is the 360-degree camera system with adaptive display - so, if you're reversing and you turn the wheel to one side, the image on screen will move, too. It'll also go between a birds-eye view and a backing-up perspective, and that can take some getting used to.

What was less convincing in terms of the user experience was the rear auto braking, which seemed to be scared of the car's own shadow. On multiple occasions the car jammed on the brakes when reversing out of driveways on to empty streets - be it in the normal height, or the raised height setting.

The 6 Series GT has dual ISOFIX anchor points and three top-tether points are there and ready for baby seats or child seats.

Like all new Mercedes models sold in 2021, the Mercedes-AMG GT Black Series comes with a five-year/unlimited kilometre warranty with roadside assist over that period.

Mercedes’ warranty easily outclasses other premium marques like BMW, Porsche and Audi, who each offer a three-year/unlimited kilometre coverage, and Lexus (four year/100,000km), while matching Jaguar and newcomer Genesis.

Scheduled servicing intervals are every 12 months or 20,000km, whichever occurs first.

Servicing costs for the Black Series were unavailable to us at the time of publishing, but maintenance of the GT coupe will ring the till up at $4750 over three years.

BMW runs a condition-based servicing plan, which means the car will tell you when it needs servicing. But you can rest assured it won't (theoretically) cost you much, with the brand's 'Service Inclusive' pack. It covers you for basic maintenance as and when required for five years/80,000km. According to BMW, that includes "annual vehicle checks, oil changes, all filters, spark plugs and labour costs for the duration of the package".

BMW offers a three-year/unlimited kilometre warranty plan, and you get the same cover for roadside assistance.