Mercedes-AMG GT S 2015 Review

At 7:30am on the first day of GT media drives, it's 2.5 degrees and foggy on top Australia's most famous motorsport mountain and Bathurst is gripped by a mid-winter (extra) cold snap and surrounded by snow.

It's supposed to be a dry time of year, say the Benz folk as light, icy rain starts to fall on the now-greasy track. Grim-faced, 72 of us shuffle into the pitlane where there is $13.5 million worth of near-new AMG glistening with dew – 63 cars in total including 12 GTs, each just run-in with 1500km under their belts.

With last night's fancy dinner in our bellies, an expensive laser light show vivid in our memories and a non-stop schedule of 300 participants across five track activities for five consecutive days, there's no stopping the three-pointed star's multi-million-dollar promotional event.

Not that we'd want to. We drove the GT at its international launch at Willow Springs in California late last year, and at the similarly challenging Norwell circuit in Queensland for our first taste on home turf in March -- enough to know that punting it around Australia's fastest, most daunting racetrack would be epic.

Now, with stern warnings from Mercedes-Benz Driving Academy chief instructor Peter Hackett about what can happen when ambitions get confused with abilities when handling 375kW with cold rear tyres at Bathurst still ringing in our ears, we're wondering just how epic it will be.

We're split up into four groups of 18 and while the others head off to warm up with trail-braking exercise at Griffins Bend and The Cutting in C 63s, tight cornering runs through The Dipper and Forrest's Elbow and back in A 45s and CLA 45s and front-straight drag races in E, CLS and SL 63s, the blue group including a handful of us journalists head straight into high-speed runs in the GTs down Conrod Straight and The Chase – Australia's fastest racetrack bend.

After rotating through all four exercises and then a couple of full laps at '70 per cent' pace in the morning, the afternoon was devoted to full-speed laps in a variety of AMGs and then hot laps in the GT with instructors, who outnumbered the guests each day.

Realistically, with just one flying lap bookended by warm-up and cool-down laps and a maximum of three sessions each in the GT S (and new C 63, which you can read about elsewhere) on a cold, drying track, it was always going to be more about the Bathurst experience than becoming intimate with AMG's first supercar since the SLS of 2010.

But what an experience it was. We'll bring you our first Australian road test of the GT and a comparo with the 911 later this month, but as we've already written, the GT is a very different super-coupe to the SLS it replaces.

It might look awkward in pictures from some angles, its rear-end appears a lot like the 911's and it lacks the sense of occassion of the gullwing-doored SLS, but close up in the metal – both outside and in -- the GT is far more beautiful than the odd-shaped SLS and exudes more presence and exclusivity than a 911, befitting it's $300K pricetag.

Yes, that's much more than a base, circa-$200K 911 and about the same as the track-focussed 911 GT3, which packs a less powerful boxer six but is quicker (0-100km/h in 3.5 v 3.8 sec) because it weighs almost 150kg less -- click here for full GT S spec details.

But the GT S is quick by any standard, makes up for any lack of performance on paper with a glorious, beefy twin-turbo V8 with instant response and zero lag, and will be joined by a Black Series flagship that should match the pace – and $365K-plus price – of the 911 Turbo.

Any doubts that AMG's new downsized M177 4.0-litre biturbo bent eight would lack the punch or pizzazz of the hairy-chested 6.2-litre atmo V8 in the SLS evaporate when you snap open the throttle in the GT S, which slams out a healthy 375kW of power – the same as the C 63 – and an even more vigorous 650Nm of torque.

That's 50Nm less than in the C 63, which lacks the GT's dry-sump design and runs a seven-speed auto with wet start-up clutch instead of the coupe's rear-mounted seven-speed dual-clutch automatic transaxle, which gives the front/mid-engined layout the same 47/53 front/rear static weight distribution as the SLS.

Although the GT S is only 85kg lighter than the C 63 S sedan at 1570kg, its broader footprint, better weight balance and new electronically-controlled clutch-operated limited-slip diff, which opens and closes continuously in the search of traction both under brakes and power, gives it an outstanding level of stability -- especially while trail-braking deep into corners.

At Bathurst, the GT S felt more planted at speed – although both cars got frighteningly light and wandered sideways over the hill going up Mountain Straight at full noise – yet its steering was also more agile, pointing the two-door more quickly into corners and holding a cornering line more readily.

In fact, I found the GT's variable-ratio hydraulic steering too light at all speeds and in all drive modes (Comfort, Sport, Sport+ and Race), and although it clearly telegraphed its intention to understeer down through The Dipper when I turned in too fast, it lacks the weight and unfiltered response of the 911's electric steering.

It will take a head-to-head track test with the 911 to separate their dynamic intricacies, but there's no doubt about the poise and precision of the GT S, which can be driven on the throttle with far more ease than you'd expect, even on the cold, damp and wildly undulating Mount Panorama surface.

It might be Australia's most formidable public road circuit, but the GT S instilled enough confidence to dance its back-end up through Griffins Bend and The Cutting in Race mode, with the highest stability control threshold allowing a decent level of yaw before subtly bringing things back in line.

Ultimately, the traction of a rear-engined 911 might make it the more effective tool to corner cleanly and perhaps more swiftly in conditions like this, but we'd wager the brawn and balance of the GT S would make it the more fun and rewarding coupe to be in when lap times don't matter.

Not that the GT S was a slouch around Bathurst -- far from it. While the cars we drove were speed-limited to 240km/h, instructors routinely saw 270km/h on Conrod and Mick Doohan was timed doing 2:26 lap times without raising a sweat.

Of course, we got nowhere near that in our limited time on track, but came away with a bigger grin than many supercars would have produced in such a short time. What should have been an intimidating experience given the circumstances turned out to be a blast, and we can't wait for our first drive of the GT S on warmer, drier Aussie roads.

2015 Mercedes-AMG GT S pricing and specifications:
Price: $294,610 (plus on-road costs)
Engine: 4.0-litre twin-turbo petrol V8
Output: 375kW/650Nm
Transmission: Seven-speed dual-clutch
Fuel: 9.4L/100km (NEDC Combined)
CO2: 219g/km (NEDC Combined)
Safety rating: TBC

What we liked:
>> Unique, exclusive design
>> Glorious, sledgehammer V8
>> High-quality interior

Not so much:
>> Costs more than a 911 GT3
>> Weighs more than a 911
>> Steering too light for us

Also consider:
Audi R8 (from $279,500)
BMW i8 (from $299,000)
Jaguar F-TYPE R (from $219,130)
Nissan GT-R (from $172,000)
Maserati GranTurismo (from $308,000)
Porsche 911 (from $208,600)

Related reading:
>> Mercedes-AMG C 63 S 2015 Review
>>