Road Test: Mercedes-Benz SL65 AMG - A beast to take your breath away
If you want to stop accelerating when you reach 155mph, then this is the
car that will bring you safely back down to earth. John Simister reports
23 November 2004
Model: Mercedes-Benz SL65 AMG
Engine: 5,980cc, V12 cylinders, 36 valves, twin turbochargers, 612bhp
4,800-5,100rpm, 738lb ft 2,000-4,000rpm
Transmission: five-speed automatic gearbox, rear-wheel drive
Performance: 55mph, 0-60 in 4.1sec, 18.7mpg official average
I flew in a Hawker Hunter fighter once. Yes, already you can guess what
is coming. But let me explain just how your first encounter with the
accelerator pedal of the Mercedes-Benz SL65 AMG brings on a sensation
akin to jet-propelled take-off.
You are taxi-ing gently along at a gentle 50mph or so. Squeeze the
accelerator - do not floor it, that can come later - feel a momentary
pause and then a whooshing roar like that of a jet engine muted through
a flying helmet and earphones. With this roar the nose rises and you are
pinned in your seat, limbs growing heavier. The view ahead compresses,
the thrust is relentless and you have to do nothing but keep your right
foot in position.
Then you have to ease off, otherwise you will either become airborne (so
you think) or you will smite something slower very hard or you will be
deprived of your pilot's licence and your freedom. But what a sensation
you have just had. It is one thing to drive a massively fast car and
work quite hard to realise its speed - you know, changing gear and that
sort of thing. But with this one you just aim, fire and hold on tight.
Maybe, if the road is not quite runway-smooth or has a few damp patches
to match those on your brow, the escape-velocity thrust is not quite so
missile-straight. It is an odd sensation to get wheelspin and a
squirming of the tail when you might be pressing the accelerator just
halfway or less, but it happens here. The electronic stability programme
(ESP) system reins it in - press pedal, hear whooshing roar, feel
squashed, sense ESP intervention, is a sequence which happens routinely
- but the forces at work are extraordinary.
With the ESP switched off, the SL65's tail will flick sideways in almost
exact concert with your right ankle's downward flick if the engine is
already pulling and you are already turning, and it is a little worrying
even if it does stop the flick the instant you ease the power. In fact
the ESP never entirely goes to sleep; it is merely attenuated when
nominally switched off, there in the background to protect us from
What is the source of this insane energy that makes this SL65 the
fastest roadster that AMG, Mercedes-Benz's official engine tuner, has
yet created? (The most expensive, too, at £145,970.) The SL600 on which
this AMG is based already has a 5.5-litre, twin-turbo V12 engine which
is surely plenty powerful enough for most tastes (500bhp, 589lb ft of
torque). And then there is the AMG version of the V8-engined SL, called
SL55 AMG and also featuring 500bhp. Clearly, though, the temptation to
apply the AMG treatment to that V12 was too hard to resist, especially
as there are power supremacy scores to settle in the rarefied world of
epically rapid and possibly pointless supercars.
So the SL65 gets extra engine capacity (now 6.0 litres, and do not ask
about the numerological mismatches), and thanks also to bigger
turbochargers blowing through an enlarged intercooler, camshafts
designed to let more petrol/air mix in and exhaust gases out, and a
free-flowing and notably sonorous exhaust system, the engine now creates
up to 612bhp. That is nearly 100bhp more than a Ferrari 575 Maranello,
poor thing. More significant still is a torque output of 738lb ft,
which, if converted to a metric measurement, shows a point being
strongly made: the figure is a neat 1000Nm (it stands for Newton metre).
Here is a car, a hefty and heavy car, which will reach 60mph from a
standstill in around four seconds. Flat out it stops accelerating at
155mph because its engine management, instructed by an informal
let's-limit-speed agreement between some car makers (Porsche, Ferrari
and Lamborghini are among those not interested), says it must. If
uncorked it might do 200mph as the rev counter touches the 6,000rpm red
sector. Which means that in the top, fifth gear of its automatic
transmission the SL65's engine is ambling at just 3,000rpm as the
speedometer touches 100mph. It also means that the SL65 is, in theory,
nearly as rapid as the SLR McLaren. As it is, that 155mph arrives in
just over half a mile from standstill.
Why make a car which is so fast? Pride plays a part, but in making a car
able to cruise effortlessly at more normal speeds - say under 100mph
with the driver exercising due prudence - a car maker inevitably ends up
with a car able to go very fast indeed when it does exert effort. Bear
in mind, too, that cars such as this AMG also have to be able to stop
from the speeds of which its capable, so they have extremely powerful
brakes. The SL65's braking distances are, I surmise, around a third of
those quoted on the Highway Code, figures long overdue for updating as
they have not been revised for a good half-century.
So, is this SL65 AMG the epitome of fast-car heaven? It has many good
points beside its crazy pace. It is beautifully made, its
automatically-folding metal roof is a fine piece of engineering, and it
looks surprisingly discreet for such a hot rod. The sound of the engine
is delicious. The semi-active suspension gives a beautifully controlled
and level ride despite the underlying firmness that comes from such
wide, low-profile tyres. And the automatic transmission works with the
mix of speed and smoothness that an ample engine makes easy. There is a
manual mode, activated by steering-wheel buttons, but with torque like
this it is hardly necessary.
For all that, though, it is not a machine of perfect dynamism. The
steering can feel uncertain and slightly disconnected at speed,
requiring more of an input than you might expect given its swift
response at a slower pace. That may be a built-in "sneeze factor" to
prevent twitches at 155mph, but it goes too far. And those brakes, fully
electronic with no direct mechanical connection between pedal and wheel,
feel springy with a long pedal travel and little feeling of something
solid to stand upon. You have to take them on trust.
But the engine remains something to marvel at, for I have never
experienced another road car engine with such an inexhaustible and
accessible supply of thrust. Paradoxically, it caused me to drive quite
sedately much of the time, relaxed and confident in the need never to
have to jockey for position in the traffic jungle. I knew that if I
needed or wanted to overtake, or get away first from traffic lights, my
wish would be granted at a mere ankle flex. Driven normally, nothing,
but nothing, outruns AMG's 612bhp V12 away from rest.
There is an S-class saloon with this engine, too. Imagine that with an
S320 CDI badge on the tail.
PORSCHE 911 TURBO CABRIOLET £96,130
A rival for the open-top side of the SL's dual personality, the Porsche
seems almost cheap in this company. It is based on the revious-model
911, extracts 420bhp from its 3.6-litre flat-six engine, has 4WD and is
a sensational drive.
FERRARI 575 MARANELLO £156,700
Another V12, this one of 5.7 litres and 515bhp. Yet it still manages
virtually SL-matching performance, partly because its six-speed manual
transmission (or the paddle-shift version of same) is more efficient. A
demanding but fabulous car.
ASTON MARTIN VANQUISH £174,000
This extensive revamp of the Vanquish, the first Aston Martin of the new
generation series, raises the 520bhp from its non-turbo 6.0-litre V12.
It is less bombastic than the SL but still hugely fast and a more
satisfying driver's car.
1 HP = 745.69987158227022 Watts
1 PS = 735.49875 Watts
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