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Audi A8
Debut: 2002
Maker: Audi
Predecessor: A8 Mk1 |
A8
used to divide opinions. Technology admirers loved its innovative ASF
(aluminum
space frame) chassis which made it the first mass production aluminum
car
in the world. They also loved its quattro 4-wheel-drive system which
was
unique in its class. Nevertheless, an honest appraisal would find it
actually
lagged behind Mercedes S-class and BMW 7-series in most important
areas,
from comfort to driver appeal. Automotive journalists concluded that
its
advanced technologies did not materialize into a Mercedes or BMW beater.
After 8 years,
Audi tried
again with the second generation A8 - or 3rd generation if you also
count
their predecessor Audi V8. This time they chose a more conservative
route.
No new technologies nor innovation was introduced. They just polished
every
components, cured the weakness and enhanced the strength. The result is
a far more matured car, if less stunning than that in 1994.
The
new A8 is no
longer fighting
its German rivals alone, because it gets a sister called Volkswagen
Phaeton.
They are built in the same factory, share a lot of components (such as
engines, transmission, 4WD and suspensions) but they have a fundamental
difference: different chassis. The Phaeton's is a conventional steel
monocoque
while the A8, unsurprisingly, favors aluminum space frame. Like A8
itself,
ASF technology has entered the 2nd generation - it has reduced the no.
of parts by half, thus reducing assembly cost as well as improving
chassis
rigidity. However, one thing is unchanged - the all-aluminum chassis
and
body is 40% lighter than steel. That translate to between 150 and 200kg
of saving.
So,
how light is it? pick a 4.2-litre A8, you will find it tip the scale at
1780kg, some 20kg and 90kg lighter than direct rival Mercedes S500 and
BMW 745i respectively. If the Audi were not 4-wheel-drive, like its
rivals,
it would have been even lighter. By the way, I always hope A8 could
switch
to rear-wheel-drive to utilize the full potential of lightweight
construction.
This could also move the engine a little rearward thus improve weight
distribution
closer to 50:50, compare with today’s 59:41. That’s why I am so eagerly
awaiting the new Jaguar XJ...
A8’s intention
to
be a major
player in the segment can be seen in its wide range of power units. It
offers a choice of 4 petrol engines and at least 2 diesels. The petrol
consists of 3.7-litre V8, 4.2-litre V8, 6.0-litre W12 and an
entry-level
3.0 V6. The diesel side includes a 3.0 V6 turbo and a very fast 4.0 V8
twin-turbo. Phaeton’s 313hp 5-litre V10 twin-turbo is also a possible.
Audi seems confident that the demand of A8 is sufficient to sustain all
these versions.
At the moment
of
writing,
only the petrol V8 duo is on sale, so let us confine our report
to
the V8s. Basically, they are enhanced version of the previous V8s,
still
employing 5 valves per cylinder, variable intake valve timing and
variable-length
intake manifolds (the 3.7-litre offers 3 stages while the 4.2 has 2
stages).
Audi didn't talk about detailed changes, but ironically these V8s have
become more efficient - the 4.2 generates 335hp instead of 310hp, the
3.7
is up from 260 to 280hp. They also drink less fuel, although not as
frugal
as BMW's Valvetronic V8s. In fact, the reduction of fuel consumption is
mostly contributed by the new 6-speed automatic transmission, supplied
by ZF. Yes, this marvelous gearbox is exactly the same one used by
7-series
and Jaguar S-Type.
With
a 6-speed gearbox and stronger engine, Audi claims 0-60mph improves to
6.0 second for the 4.2 V8, a bit faster than its direct rivals. With a
drag coefficient of 0.27, the car can slip into 155mph air flow without
generating much wind noise.
On
the road, the
4.2-litre
V8 never disappoints. Like that of BMW 745i, it is near-silent at
cruising
speed but can also emit a sporty growl when being pushed. It might not
match BMW’s fuel efficiency and superior torque curve, but by any
standard
this is still a very good engine. Powerful yet refined. The 6-speed
Tiptronic
gearbox shifts seamlessly.
In corners,
the
new A8 continues
to impress. You won’t doubt the superior traction and grip offered by
the
4-wheel drive, what you can’t believe is how nimble it behaves in
corners.
You know many Audis - RS6 and S4 included - feel nose heavy, but the A8
has none of such feeling. It turns into corners keenly, feeling far
smaller
than lighter than its actual size suggests. Its steering is crisp and
accurate.
At low to medium effort, it remains fairly neutral. Only at the limit
it
will run into safe understeer, which is a good thing for a luxurious
car.
What did Audi
do?
look at
the suspensions - front 4-links, rear trapezoidal-type multi-link,
low-unsprung-weight
alloy suspensions arms... none of these are the reason, because they
were
carried over from the previous generation. What made the difference is
a 60% stronger chassis as well as the addition of Mercedes-style
adaptive
air springs and adaptive dampers. Whenever you want to enjoy handling,
suspension setting is stiffened automatically to reduce pitch and roll.
That’s why A8’s chassis feels better sorted out than other Audis. On
the
other hand, whenever you want to enjoy comfort, the softened damping
and
air springs work pretty well to filter out unwanted harshness. The
result
is a ride quality smoother than 7-series while not much behind the
super-smooth
S-class.
Talking
about comfort, A8 seems not the last word in the segment. To prevent
internal
competition from Volkswagen Phaeton, A8 biases towards driver appeal
rather
than luxury. That doesn’t mean it were uncomfortable. In fact, it
offers
all things you expect in this segment, from space, comfy chairs,
equipment
to quality material. What it lacks is a sense of occasion. The interior
design is no more special than an A6, this could hurt those who pay the
extra in pursuit of something really luxurious.
Relatively,
I
prefer the
exterior. It might be not as pure as its predecessor, but it is still
handsome
enough. From far away, it looks like a grown-up A4, with length
stretched
to over 5 meters. Unlike the BMW 7-series, its body profile looks
sporty
and smaller than it is. Closer, you will appreciate its high quality
build
(e.g. fine assembly gaps and uniform paint) and attention to details. A
lot of chromed frames deliver a sense of prestige which you cannot find
in a S-class as well as 7-series.
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MMI
(Multi-media
Interface) is
Audi’s version of iDrive. However, it is more user-friendly than BMW’s
system, which has been notorious. Like a computer mouse, MMI uses a
rotary
control and buttons to navigate menus in the LCD screen, getting
access to various functions, such as video, audio, satellite
navigation,
telephone etc. |
The Verdict
Right now, Audi
A8 has to
beat 2 rivals in order to top the class. First one, the reigning
champion
Mercedes-Benz S-class. Surprisingly, the big Benz achieves an even
better
balance between handling and ride. It loses nothing to the Audi in
handling
contest while winning the ride comfort test. Its rear passenger space
feels
much bigger, but it also lose a lot of marks in material and build
quality.
The second
rival,
BMW 7-series,
still has an edge in driver appeal. Its active anti-roll bars and
sportier
setting of suspensions result in flatter and sharper cornering. Its
Valvetronic
V8 also wins by a small margin. However, it also sacrifices too much
ride
quality to achieve sporty handling.
Compare with
them, the Audi
is surprisingly all-rounded. It performs well in nearly all areas,
although
it doesn’t top any area either. Overall speaking, it is a more
convincing
choice than the BMW and runs neck to neck with the mighty big Benz.
Most
important, the new A8 has finally got out of the shadow of its rivals
and
become a formidable player in the luxurious segment.
Congratulation
to
Audi A8,
the first Audi car that tops AutoZine’s rating.
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The
above report was last updated on 15 Jan 2003. All Rights Reserved. |
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A8 W12
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In
my opinion, 12-cylinder engines are rather unnecessary for luxurious
saloons.
They are more the symbol of status, showing how superior the car is and
how wealthy its owner is. In fact, most of their owners never need
those
400-plus horsepower and 5-second 0-60mph acceleration.
However,
as arch-rival Mercedes has S600 and BMW has 760Li, Audi needs to
respond
with a 12-cylinder A8. This is not the first ever W12 A8, as the engine
was also briefly used in the previous generation A8. Its
W-configuration
is implemented by mating a pair of narrow-angle VR6 at 72°. This
results
in a very compact package, measuring about the same length as an
inline-4
engine. 4 camshafts operate 48 valves, all with variable timing. It
produces
450 horsepower and 428lbft of torque, exceeding the old engine (which
is
still being used by Volkswagen Phaeton) by 30 horsepower and 13 lbft.
Even
though the car weighs a hefty 2 tons, Audi estimates the W12 can push
the
car from 0 to 60mph in 5 seconds flat. That’s faster than BMW 760Li but
slower than the 500hp Mercedes S600. Again, few people need that kind
of
explosive performance.
What customers
actually want
is higher level of comfort, which is less successful in the flagship
A8.
While the regular A8 is never renowned for ride comfort, the W12 rides
even stiffer, blame to its wider and lower profile tires. Customers
expect
more smoothness and quietness from the powertrain, but the W12 is
actually
more throaty than the V8 and brings no extra smoothness. Being a
flagship
limousine, this is inevitably disappointing.
The
only thing the W12 matches our expectation is space and quality.
Available
in only the long wheelbase body, its extra 13cm wheelbase provides
superior
space at the rear - more than people actually need. The high quality
plastics,
wood and leather, and the classy fit and finish of the whole car
continues
the tradition of A8. Unfortunately, the huge grille - unique to the W12
- looks muscular rather than graceful. It actually devalues the
originally
handsome look.
In
fact, a long
wheelbase
A8L 4.2 is more convincing than the W12 to fulfill the need for luxury
and comfort. It is a lot cheaper too.
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The
above report was last updated on 11 Mar 2004. All Rights Reserved. |
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Audi S8
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3
years after the launch the current generation A8, Audi
finally introduces its sporting version, S8.
Unlike the last generation S8, the new car no longer uses a sport-tuned
4.2 V8,
but adopted a detuned version of Lamborghini Gallardo's V10 engine -
don't
forget the Lamborghini engine is actually developed by Audi based on
the
architecture of its 90-degree V8. With a bore enlarged by 2 mm, the V10
has its
capacity increased to 5204cc. This help it to increase maximum torque
from the
Lamborghini's 376 lbft to 398 lbft. The max torque also occurs at lower
rev,
now 3500 rpm instead of 4500 rpm. Moreover, 90 percent of the peak
torque is
available from 2300 rpm.
Power, however, is detuned to 450 horsepower at 7000 rpm (Lamborghini:
500 hp at
7800 rpm). Strangely, the Audi engine retains the dual continuous VVT
and
2-stage intake manifolds of the Lamborghini V10. It even added FSI
direct
injection to raise compression ratio to 12.5:1. But the emphasis is on
a wide
spread of torque, lower fuel consumption and reasonable cost – as it
does not
need to rev as fast, lightweight pistons and connecting rods are no
longer
necessary.
Strangely,
450 horsepower is no more than the A8 6.0 W12.
Audi claims both cars accelerate from 0 to 62 mph in 5.1 seconds and
both's top
speed are electronically limited to 155 mph. So, how to distinguish
them? The
W12 is the luxury flagship, while S8 is the sportiest A8. First of all,
it is
20 kg lighter than a SWB W12 (don't laugh). Then, its suspensions are
tuned sportier
- stiffer and has 20 mm lower ride height. Its steering is made 10
percent
quicker. Its new Quattro drivetrain - like that in the new RS4 -
delivers 60
percent drive to the rear wheels normally. Its brakes are larger (385
mm front,
335 mm rear) and can be chosen with ceramic discs. Its wheels measure
20 inches
and wear 265/35 tires. Besides, its Tiptronic gearbox has a lower final
drive
ratio to deliver quicker response.
That's
enough
to lift it above its brothers, but what about
BMW M5 ?
The
BMW
V10 cranks out 507 horsepower to push 1755 kg. The
S8 relies on 450 horses to pull 1940 kg. They are not in the same
performance
level at all. While we can describe M5 as a 4-door supercar, the same
cannot be
said to the S8. Yes, 4.9 or 5.0 seconds to 60 mph is still very fast,
but not
fast enough to be the company's top performer - that should be the
smaller RS4.
Like the
last generation S8, or the outgoing Mercedes S55
AMG (to be replaced by S63 AMG), the new S8 does not intend to be a
full-blooded performance sedan. Instead, it wants to make a compromise
between
luxury and performance. From this viewpoint, it does quite well. It has
the
most tasteful design in the class - especially enhanced by the larger
wheels
and the tail spoiler. It has the highest build quality. It has a
Tiptronic
automatic transmission and 4-wheel-drive to deliver effortless and
trouble-free
performance. Its air suspensions and adaptive damping provides a firm
but
composed ride. Moreover, being a class higher than M5, its cabin offer
more
space and luxury.
However,
it
does not engage its driver through the helm or
through the way it respond to driver's input. With the whole V10
hanging over
its nose, the S8 is not an inherently balanced machine. While the
chassis
tuning and electronics hide most drawbacks very well, they cannot
deliver a
sharp handling and a communicative steering like a well-sorted
rear-drive
machine. The size and weight do not help either. This means the S8
prefers fast
bends rather than the twisties.
Externally,
S8
can be easy to confuse with other A8s. The
easiest way to distinguish it is from the single-frame grille, which
has unique
chrome finish at the vertical bars. The air intakes below the grille
are also
different from other A8s, as is the bigger wheels and a tiny spoiler
incorporated at the trailing edge of boot lid. Many people prefer this
"understated beauty". But will they also prefer its "understated
driver appeal" and "understated performance" ?
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The
above report was last updated on 21 Dec 2005. All Rights Reserved. |
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