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flapship sports car of Mercedes-Benz goes progressively downstream over
the last decade, from the £313,000 SLR
McLaren to the £170,000 SLS AMG
and now the £100,000 AMG GT (or £110,000 for the hotter GT
S). This means it now clashes head-on with the mighty Porsche 911 in a
much bigger market segment. Stuttgart has not revealed sales target,
but obviously it is looking for more than 10,000 units annually,
considering Porsche sold 30,000 units of 911 last year. In other words,
one year of sales will easily match or exceed that managed by the SLS
in its entire lifespan of 5 years.
The business case is more sensible not just because of keener pricing,
but the new market positioning is more relevant to the existing line-up
and customer base of Mercedes. The old SLS used to have an identity
problem – it did not have a badge as exclusive or exotic as Ferrari yet
it commanded the same price as the excellent 458 Italia. Just like
Ferrari California, it was a mismatch of badge and talent. Now the
reposition puts it at a market segment which demands solid build
quality, luxury and everyday usability as well as performance and
driving thrills. For long, Porsche 911 had been the only choice for
this class. In recent years Audi R8, Aston Martin V8 Vantage and Jaguar
F-Type R joined the competition but none of them quite rocked the
status of Porsche. Can the AMG challenger do that?
Style-wise, the AMG GT is a bit more handsome than the SLS. Its body
profile gets smoother, with a rounder nose, roof and tail, while a
hatchback design is adopted instead of 3-box. It even looks a bit like
911 from the tail. The details have also evolved to be more elegant.
However, it keeps the same long-hood, short-deck, cab-rearward profile
of the old car as the mechanical layout is unchanged, i.e. a
front-mid-mounted V8 and a rear-mounted 7-speed dual-clutch transaxle.
Because of this, it also keeps the same excellent front-to-rear weight
distribution of 47:53. On the downside, this Jaguar-E-type-like profile
is not kind to airstream, thus its drag coefficient is rather poor at
0.36, a far cry from the high standards of Mercedes – no wonder it did
not mention in press release. A tiny tail spoiler raises automatically
at speed to cut lift.
At 4546mm, the car is 92 mm shorter than the SLS, though its width is
the same at 1939 mm, and it is a bit taller at 1289 mm. The latter
gives its cabin more headroom, especially when the seats are set a bit
deeper. To ease access to the cabin, save weight and cut costs, the
SLS' gullwing doors have been replaced with conventional hinged doors.
Just like the exterior, the cockpit of AMG GT looks classic yet
elegant, perhaps even flamboyant. It is dominated by 6 large circular
air vents, a wide transmission tunnel and chunks of flashy decors. The
space offered is tight, because the upright windscreen is close and
there is virtually no clearance left behind the seats. Unlike 911, the
AMG GT is strictly a 2-seater, but it has a reasonable boot measuring
350 liters, which could swallow a couple of golf clubs through the
hatchback. You sit low and, compared with 911, visibility is limited by
the high waist line, long bonnet and thick rear pillars. In other
words, some practicality is traded for sense of occasion. Otherwise,
ergonomics is quite good, thanks to plenty of adjustment to the seats
and steering wheel and the high-mounted touch screen. Build quality is
exceptional for this class, at least matching Porsche. It is tastefully
trimmed with leather, Alcantara, alloy and optional carbon-fiber. Many
switch gears are bespoke to the car, while those coming from Mercedes
parts pool are far from disgraceful.
The all-aluminum chassis is a further development from the SLS.
Mercedes claims it is the lightest in class at 231 kg. The whole car is
80 kg lighter than SLS and 55 kg lighter than 911 Turbo (though the
latter has 4-wheel drive and rear seats). All suspensions are classic
double-wishbones type. Their wishbones, knuckles and hub carriers are
made of forged aluminum. The front suspension is taken from SLS,
whereas the rear is a new design, with the lower wishbone connected
directly to the wheel carrier for better wheel control. Adaptive
dampers are standard to the GT S and optional on the lesser car. The S
is also benefitted with an active rear differential (instead of
mechanical one), Porsche-style variable engine and transmission mounts,
stronger brakes and beefier rubbers. These add 30 kg to its kerb
And it gets more power, too. We all love the old 6.2-liter V8 for its
great sound, revvability and outright power, but unfortunately it has
been phased out of production under the pressure of reducing emission.
Taking its place is the new AMG M178, a 4.0-liter twin-turbo V8. It
shares the same bore/stroke dimensions (83.0 x 92.0 mm) and many key
features with the 2-liter turbo on A45 AMG. These include spray-guided
piezo direct injection, 10.5:1 compression, twin-VVT, a cylinder head
made of zirconium (for better cooling), cylinder bores treated with
nano-slide low-friction coating and forged pistons. Unlike the versions
to be fitted to other AMG saloons and coupes, this one has dry-sump
lubrication to let it position lower in the chassis and deals better
with cornering g-force. To keep its size compact, its turbos are
mounted inside the V, like the latest V8s of BMW and Audi. In standard
form it boosts up to 1.2 bar, producing 462 hp at 6000 rpm and 442 lbft
of torque from 1600-5000 rpm. On the hotter S model, boost pressure is
lifted to 1.3 bar to produce 510 hp at 6250 rpm and 479 lbft of torque
at 1750-4750 rpm. Responsible for transmitting the power is a Getrag
7-speed DCT, a development from the old car.
The GT S is good for 193 mph and 0-60 mph in 3.7 seconds, very close to
the level of 911 Turbo. It’s not exactly there yet, because Mercedes is
holding its potential for the upcoming GT3 and Black Series variants.
Considering the AMG 2-liter turbo is good for 180 hp per liter, the
4-liter V8 is theoretically capable of 720 hp! Apparently, the GT S is
only the starting point of development…
On the Road
Even as a starting point, the new twin-turbo V8 is already a good one.
There is a little bit turbo lag at low rev to overcome, more than the
VTG turbos of Porsche, but the power delivery is surprisingly linear
for a turbocharged motor. AMG deliberately mapped its ECU to give this
linear character, therefore makes it friendlier to exploit and feel
like a normally aspirated V8 – the same tactic as Ferrari on California
T. The V8 is flexible across the entire rev range. It revs sweetly
towards the 7000 rpm cut-out, although you won’t get any more punch
beyond 6250 rpm. The exhaust note tuning is another wonder.
Mercedes-AMG is still the only one capable of giving a turbocharged V8
such a wild, bassy, NASCAR-like soundtrack. If you have never heard how
the old 6.2 sang, you might mistake it with a good normally aspirated
The AMG GT certainly feels very fast on the road, thanks to the
immensely flexible engine as well as the much improved dual-clutch
transaxle. It might share the same hardware with the old one, but its
calibration makes a big difference, giving determined and responsive
The handling is much improved over the SLS. It feels lighter, more
agile and more accurate to turn. No doubt AMG has learned from mistakes
and spent more effort on the chassis tuning. Unlike its predecessor,
its tail doesn’t breakaway easily, thanks to much enhanced traction and
grip and tighter body control. When it starts sliding, it is more
progressive, and you can adjust the attitude with throttle. Now you can
finally push the AMG as hard as a Porsche or Ferrari in a race track,
enjoying its fluid maneuvering and new found composure. The
variable-ratio steering is progressive and precise, with decent if not
first-rate feel. Automobile magazine praised it as “the best of any
electrically assisted system today, Porsche included” because, well, it
is actually a hydraulic rack – applause to AMG as it dares to resist
the trend of EPS.
However, the 911 remains the better sports car. Although the AMG GT S
is much improved over its predecessor, the Porsche is still more agile,
sharper and more precise in control, especially the rear-drive normally
aspirated models like GT3 or GTS. More surprising, the 911 rides
better, too. That leads to the biggest flaw of the AMG: its suspension
is simply too firm for modern sports cars, let alone one dubbed “GT”.
On slow roads filled with bumps and portholes it rides uncomfortably
even with adaptive dampers at the softest setting. Neither does it feel
as composed as Porsche at high-speed cruising. This hurt its prospect
as a cross-country GT. The lack of composure could also hurt its
handling on less than perfect roads.
This and the cramped interior/mediocre visibility are the only
reservations about the car. The GT counters with a unique style, high
build quality and an excellent V8. It is certainly worth consideration
if you look for something different to the mainstream 911. One thing is
certain: it is a lot better than Mercedes’ last attempt yet
considerably cheaper to buy.
| Published on 21
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| AMG GT R
GT R – not to be confused with Nissan GT-R – is the fastest version of
the AMG sports car until the ultimate Black series to arrive in a
couple of years’ time. This means, it sits above the standard 462 hp
GT, the 510 hp GT S and 557 hp GT C in the increasingly crowded
hierarchy of the AMG GT family. The GT R is not only faster but it is
also track-oriented, like Porsche 911 GT3 RS. You can easily see that
from its shape, which gets a lot more aggressive and aero-biased. Its
front grille has been enlarged to aid cooling and gets some vertical
grille elements which are reminiscent of the 1952 300SL Panamericana
race car. The lower intakes also get larger. The front air splitter is
set lower and more pronounced. At both sides of the bumper are two
narrow, vertical intakes which draw air to form "air curtain" around
the front wheel arches to reduce drag and turbulence. At the rear, the
most obvious change is the fixed carbon-fiber rear spoiler. The exhaust
is now centrally mounted to make space for 2 large diffusers at either
side of it. Between the taillights there is an additional air outlet
opened to release hot air. AMG GT has always been a beautiful design.
The R remains beautiful, but it replaces some grace with anger.
Although the big rear wing is only manually adjustable, some active
aerodynamic aids are used elsewhere. At the bottom of the front
overhang there is a movable carbon-fiber flap which can be lowered if
the road is absolutely flat (it is activated at Race mode above 80
km/h). This creates venturi effect and guides the underbody air flow
more effectively to the rear diffuser, resulting in 40 kg more
downforce at top speed. Overall, the car makes 155 kg of downforce at
top speed and a drag coefficient lower than the standard car –
admittedly, the latter is not too difficult to achieve considering the
standard car has a poor Cd of 0.36!
You might notice the car looks wider than before. Yes, the bespoke
carbon-fiber front fenders and aluminum rear fenders increase its width
by 46 and 57 mm respectively to house wider tracks and tires. The tires
are now 10mm and 20mm wider front and rear respectively, and they are
stickier Michelin Pilot Sport Cup 2 rubbers like 911 GT3 RS. They are
shod around lighter forged alloy wheels.
The engine is still that 4.0-liter twin-turbo V8. Larger compressor
wheels lift its maximum boost pressure from 1.2 to 1.35 bar.
Accompanied with revised exhaust ports and compression ratio etc.
results in 75 more horsepower, so the total output is 585 hp. It’s not
quite as powerful as the latest E63 S (612 hp) as it lacks the latter’s
twin-scroll turbos and enhanced intercooling in exchange for lighter
weight and smaller packaging. The V8 breathes through a new lightweight
titanium exhaust. Power is coupled to a lighter twin-mass flywheel and
7-speed twin-clutch transaxle. A taller first gear makes it more useful
at launch, while shorter top gear and final drive results in quicker
response and explains why its top speed is only 5 mph higher. The
traction control is reprogrammed to offer 9-way adjustment.
The torque tube linking between engine and transaxle is now made of
carbon-fiber instead of aluminum in the case of the standard car. The
transmission tunnel is reinforced by carbon-fiber elements to increase
the chassis' torsional rigidity by 7.5 percent. The diagonal braces in
engine compartment have been converted to carbon-fiber as well.
The suspension of GT R keeps the forged aluminum control arms and
knuckles etc. but it turns to manually adjustable coil-over
spring/damper units to alter roll and dive characteristics.
Continuously adaptive dampers remain. The rear suspension is added with
Mercedes' first active rear-wheel steering in order to tame its
handling and match Porsche. Also like Porsche, it gets adaptive engine
and transmission mounts to limit movement of these heavy components at
hard cornering. Braking is provided by "composite" discs (i.e. steel
disc with aluminum hub) in size of 390 mm front and 360 mm rear, but
for occasional visits to track, the optional ceramic brakes are
Finally, the GT R is only 15 kilograms lighter than the GT S, not
particularly stripped-out for a track-oriented car. It keeps most
creature comfort intact, so weight saving comes from mainly the
titanium exhaust, lithium battery and carbon-fiber roof/front
fenders/spoilers/torque tube etc. The fine static balance of 47:53 is
unchanged, thanks to the transaxle layout.
On the road
How does it drive on track? Impressive. It is really fast, not only a
lot faster than the GT S but also many rivals. Porsche said 991 GT3 RS
good for a 7:17 lap in Nurburgring, but this AMG has just set a
rear-wheel-drive production car record there at 7:10.9, faster than
Gumpert Appollo (a thinly disguised race car, remember), Viper ACR and
Lexus LFA Nurburgring. Only the all-wheel-drive 918 Spyder, Lambo
Aventador SV and Nissan GT-R Nismo had been faster.
The V8 remains one of the most intoxicating elements of the machine as
it is so responsive, willing to rev, and it makes really great sound,
especially the mad pops and crackles at overruns. However, unlike the
lesser models, the GT R now has a chassis to match. Its Cup tires offer
a lot more grip. Traction is excellent for a front-engine rear-drive
car, if not as impressive as mid-engined Ferraris or McLarens. Turn-in
is much sharper. Roadholding is much stronger. Body roll is much
tighter thanks to the stiff suspension setting. When it finally breaks
away from the tarmac, its behavior is much more progressive, no doubt
thanks to the 4-wheel steering. Compared with its siblings it has less
understeer to overcome and a lot less drama to deal with when the car
start sliding. On a track you can still manage the drift angle with
throttle, but it is no longer the inherent nature of the car, because
slide is the enemy to speed. You can push the GT R much harder on the
track, brake later and reapply power earlier at corner exit. It has
lifted performance to a whole new level – a level not far below the
likes of 488GTB and 570S. It is a precise track machine, a rare
achievement for an FR sports car.
However, with price starting at £142,000 (and can easily top
£160,000 with ceramic brakes and other options), the GT R falls
into a highly competitive class where many rivals are equally good. The
AMG isn’t the quickest in straight line. Its steering doesn’t offer the
best feel. Its dual-clutch gearshift is good but not as great as
Porsche's. Neither is its traction as impressive. As much as we love
the AMG M178 V8, it is not as sweet as the naturally aspirated boxer of
911 R. Most important, the GT R is more a hardcore track machine than
anyone else. On less than perfectly smooth roads you will find its ride
so stiff, even in Comfort mode, something McLaren 570S, Audi R8, 911 R,
911 Turbo S or Honda
NSX managed to avoid. That’s the price of Nurburgring lap record, and
what keeps it from matching its more rounded rivals.
| Published on 19
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| AMG GT C
might just be the sweet spot of the increasingly vast AMG GT family...
does C stand for? No one knows, not even Mercedes itself. Never mind,
what we need to know is that it bridges the gap between the GT S and
the track-oriented GT R. It might just be the sweet spot of the
increasingly vast AMG GT family.
The GT C was initially unveiled as a Roadster, but hard top coupe
joined shortly afterwards. Naturally, the Roadster is slightly heavier
(by 35 kg) due to the soft top mechanism as well as some chassis
reinforcement surrounding the cockpit. It sacrifices merely 1 kph on
Autobahn, but in terms of handling and ride you will be hard pressed to
tell the difference because the chassis feels just as stiff as the
coupe. Both are powered by the familiar M178 4.0-liter
hot-Vee V8, whose state of tune lies halfway between GT S and GT R. Its
maximum output is 557 horsepower, while peak torque is 501 lbft. By the
way, the base GT and GT S also enjoy a slight power boost recently (see
grille makes the car look angrier and more purposeful.
All AMG GTs now sport the so-called “Panamericana” grille like the GT
R. It makes the car look angrier and more purposeful than the original.
Unlike lesser models, the GT C also follows the exotic GT R to employ
flared rear fenders which extend its body width by 57mm. They enable
a wider track and 10mm wider rear tires. Like GT R again, the C is
with 4-wheel steering as standard, something improving its handling
significantly. However, it does not enjoy the carbon-fiber diet of the
range-topper. A GT C coupe tips the scale at 1625 kg, 55 more than the
GT S. This is mainly down to the 4WS, the standard fitted adaptive
dampers and active differential. For comparison, a 911 Turbo S weighs
25 kg less despite its 4-wheel-drive system. The Porsche is also
slightly more powerful, no wonder it could claim 0-60 mph in 2.8
seconds, significantly faster than the GT C's 3.6 seconds.
Standing start acceleration has never been the strength of AMG GT due
to its FR layout. However, in the real world the GT C never feels
tamed. Its V8 howls angrily, especially with the variable exhaust opens
its flaps. Benefited from the rear-wheel steering and wider rear track,
its chassis balances much better. A GT S would understeer at the corner
entry and then slide its tail if you commit too much at corner exit.
The GT C corners smoother, with less initial understeer to deal with,
and oversteer is much better contained. It is now a lot more
predictable to push at tighter turns, even though it still can't match
the traction and agility of 911 Turbo.
chassis balances much better...
The suspension rides firmly, but not as firm as the GT R. It is not
going to be as comfortable as NSX, 570S or 911 Turbo on daily commute,
but still easily acceptable for hardcore drivers. On the plus side, not
many rivals could match the AMG’s visual appeal. Its exterior design is
full of character. Its interior feels expensive and special. The
Roadster’s 3-layer fabric roof is high-quality and the Airscarf seats
keep your neck warm in winter. This means, although it costs the same
as the 911 Turbo S and NSX, some people might find its packaging more
than enough to compensate for its performance deficit.