Kia Stinger vs Mercedes-Benz AMG GT

What's the difference?

The Stinger GT-Line is a great machine. It looks good, feels good to drive and while it's not the cheapest large sedan, it's also not a Camry. With a strong European vibe, it's a nice bridge between boring-dependable and out-of-reach European. Boasting a strong link to Europe in its chassis DNA, it has it all apart, maybe, from the badge.

But Kia has a habit of doing unexpected things and the Stinger was a bold move worth making just for the halo effect of having such a cool car in the range. It has done good things for the company's reputation, as though the rest of the range isn't proof already.

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.

The Stinger looks fantastic. I know the car has its detractors, but there's a massive Euro influence here that sits well in my visual cortex. It's maybe not as ooh-aah as the A5 or the outgoing BMW 4 Series Gran Coupe, but the Stinger can and should be mentioned in the same breath. It looks terrific, even if it is a bit fussier in the details.

From the signature grille, the low beltline, big wheels and sports coupe roofline, it looks sleek and sophisticated. 

Inside is a bit more conventional, with some real classic touches such as circular air vents, conventional-looking gear selector and a flat-bottomed steering wheel. It's cool, clean and, with the big new screen, a bit more techy-looking than before. There are lots of nice materials and the odd rogue one, but it's a good cabin that feels well put-together.

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.

This is really a four-seater car. While there is good legroom in the rear, the falling roofline, small door aperture and huge transmission tunnel box you in a bit, almost rendering the middle seat useless for all but the shortest of folks. You do get your own air vents, though, which is generous.

The low roof also means limited headroom, made a little worse by the standard sunroof. I had room but taller people might brush the headlining. There are two cupholders front and rear for a total of four and each door has a bottle holder.

The boot is a modest-for-this-size 406 litres, rising to 1114 litres with the seats down. Access to the boot is good if not spectacular; the hatch opens wide but a slightly narrow aperture means loading and stowing flat packs and things like that could be a struggle.

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 GT-Line's bonnet is Kia's Theta II 2.0-litre four-cylinder turbocharged engine. It's the same as before, with a stout 182kW and 353Nm. Driving the rear wheels is an eight-speed automatic from the Hyundai-Kia empire.

It's pretty rapid, knocking out the 0-100km/h spring in just six seconds, a mere 1.1 seconds slower than its faster sibling's 4.9 for the benchmark.

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.

Kia's claimed combined cycle figure is 8.8L/100km. As the Stinger goes without trickery like stop-start or mild hybridness, it's no surprise that my week with it yielded an indicated 10.4L/100km, which isn't bad for a 1750kg sports sedan that was not molly-coddled and also spent some time in a resurgent case of crap traffic in Sydney.

It also drinks standard unleaded, which is a nice touch.

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.

I have driven and loved the Stinger GT. It's tremendous fun, goes like a rat running away from a cut snake, which itself is being chased by a mongoose with its bottom on fire, and it handles like a proper sports sedan.

The GT-Line is obviously not that quick, but it's not slow, either. But it does take a bit of the GT's DNA and delivers a driving experience eerily reminiscent of an E90 BMW 3 Series. That seems like an out-of-date reference, but it was a beautiful car to drive with a lovely balance of ride and handling.

The steering has good feel and you know what's going on underneath the front wheels. You sit towards the centre of the car, also a BMW trademark. Turn the wheel and the car goes with you, despite its bulk, and it's happy to dance a bit with its limited-slip diff.

The 2.0-litre turbo does a good job in most conditions but you feel it coming up short when you're hustling it. It's never breathless, but the torque deficit to the turbo six is clear. If you've not driven the faster Stinger, you may not notice, but there's a touch of lag in the 2.0 that contributes to the idea it's working hard to move the big sedan.

But back off a little and it becomes a fluid, fun drive. In town it's firm but very comfortable, gently bumping rather than crashing into potholes. The rear suspension is a complicated five-link set-up that costs money and eats into boot space but delivers the goods.

Given its length the Stinger is a bit tough to manoeuvre in tight spaces and its 11.2m turning circle isn't too flash either, but you soon get used to it.

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.

Kia's ground-breaking seven year/unlimited kilometre warranty along with roadside assist for the first 12 months. Each time you service your car at Kia, you get an extension on your roadside assist for up to eight years.

Perhaps the only thing that makes you go, "Oh, what?" about the Stinger is the 12 months (Good)/10,000km (Oh...) service intervals. That's pretty common with Kia's turbo engines but is a little inconvenient. Then there's the cost - prices range from $312 to $685, which adds up to $3459 over the first seven services. If you stay under 10,000km/year, that's not bad going at under $500 per year for servicing, but if you're a high-miler, it will add up.

The servicing isn't outrageous - and the prices are capped - but it's not cheap, either.

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.