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Mercedes A-class (W169)
Debut: 2004
Maker: Mercedes-Benz
Predecessor: A-class (W168)
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 In
1997, Mercedes stunned the world by introducing A-class to the world.
People
could not believe Mercedes would bring such a small car to the market,
rivaling Volkswagen Golf in the mainstream market. They were also
stunned
by its innovative design and packaging - a revolutionary "sandwich
floorpan"
structure enables a very compact body yet provides a lot of cabin room
and unrivalled crash protection.
Sandwich
structure is probably
the most ingenious packaging concept since Sir Issigonis' Mini. It is
called
"Sandwich" because the horizontally orientated engine is laminated
between
the floorpan and the cabin, just under the driver’s feet. As a result,
the cabin floor is raised by a massive 200mm. That explains the
A-class’
tallness. What is the advantage of such structure? first of all, it
allows
the A-class to pass any foreseeable crash test easily. This is because
in case of collision the engine will be pushed under the cabin instead
of towards the driver’s legs. Secondly, thanks to this superior crash
protection,
A-class does not need to provide a large crumple zone up front, thus
allows
an extremely short front end and a very compact overall length.
Thirdly,
the raised cabin is less obstructed by the front wheels, therefore the
cabin can be pushed much forward to enhance interior room.
Nevertheless,
sandwich structure
has its weakness too. It made the A-class too tall, led to the rollover
crisis in 1997. Mercedes eventually solved the problem, but in the
process it introduced severe understeer and a stiff ride to the
A-class,
ruining its original sweet driving manner. Still, once it restored
customer
confidence, some 1.1 million cars were sold.
Now here comes
the second
generation A-class. Mercedes is even more ambitious with this project,
planning to sell 300,000 examples annually for the following 6 years.
The
basic philosophy is unchanged - sandwich structure is carried over -
but
this time the focus is to correct its faults in ride and handling.
Without
altering the overall height, Mercedes increased the tracks of A-class
considerably
(53mm front, 99mm rear) to enhance its cornering stability. The
torsion-beam
rear suspension is an all-new design. It features a Watts link for
better
wheel control, while revised geometry put the roll axis closer to the
center
of gravity. These modifications reduce body roll a lot. At the
MacPherson
front suspensions, a tower brace and a new link between anti-roll bars
stiffens the whole structure and separates the longitudinal and
transverse
forces better, hence improving steering precision.
 All
these changes made a big difference to the handling. The A-class now
understeers
less and controls its body more tidily. Body roll is reduced and
becomes
more progressively, giving its driver plenty of confidence. The
speed-sensitive
steering is beautifully weighted, light at town and weighs up at speed.
It steers the car precisely yet delivers plenty of feel to the
driver.
The
combination
of extremely
compact body and light steering is perfect for city driving. However,
on
German highway the A-class also displays remarkable high-speed
stability,
thanks to the new mechanical adaptive dampers. In the twisty, it won’t
match a conventional hatchback due to its MPV-like center of gravity,
but
then again many hatchbacks cannot match its fine steering and
predictable
manner.
And
what about
ride quality
- the weakest area of the former A-class? happily, thanks to the more
sophisticated
suspensions, the new A-class no longer needs stiff springs and dampers
to prevent from rollover. Instead, a softer setup and longer travel
suspensions
result in a supple, compliant ride. Audi A3 and BMW 1-series must be
jealous
how cosseting and quiet it rides, especially at low speed.
Externally,
the
new A-class
keeps the original car’s lovely shape and evolves to cleaner and more
streamline.
The monospace profile and unique C-pillars are still its trademarks,
although
increasingly imitated by others. An even prettier 3-door version has
been
added, but it actually measures the same dimensions as the 5-door.
Compare
to the Mk1 they are 232mm longer and 45mm wider. This increases cabin
space
a lot - 97mm more shoulder room, 12mm more front headroom and 30mm more
rear legroom. Its 2568mm wheelbase is closer to the old A-class LWB
(2593mm)
than the old standard car (2423mm).
Ridiculously,
the A-class is actually roomier than C-class. This must thanks to the
sandwich
structure. Luggage space now grows to 435 litres. Fold the rear seat
and
it expands to 1995 litres, almost like a real MPV.
 The
A-class might look like a MPV, but its driving position is by no means
MPV-like. The vertical steering wheel, the tilt seats, the position of
dashboard and pedals in relation to the driver all work like a normal
car.
However, what we care most is the build quality. In the past decade,
Mercedes
was widely criticized for downgraded quality to boost profit. That was
especially serious for the cabin’s materials and switch gears.
Recently,
we saw a revival of quality in the new SLK. Is it a U-turn in
engineering
policy or just an individual incidence? the new A-class told us it is
the
former. Quality has really come back to Mercedes-Benz ! look at that
soft-touch
plastic dashboard, the chromed details, the damped switches (many comes
from the recently facelifed C-class)... this cabin finally deserves the
name "Mercedes-Benz".
In contrast,
the
engines
are perhaps the least Mercedes-like. They are not shared with other
existing
models because they are designed for mounted transversely and drive the
front wheels, in contrast to the company’s tradition of longitudinal
engine
/ rear-drive. 4 petrol engines are offered: 95hp A150, 115hp A170,
136hp
A200 and lastly, a new hot hatch version A200 Turbo which produces
193hp
and 207lbft ! Mercedes is confident that the new chassis can handle the
extra power. These engines employ aluminum head, block and pistons to
achieve
a remarkably light weight (92kg for A150 and 117kg for A200 Turbo).
Despite
of just sohc and 2 valves per cylinder, they run at a 11.0:1
compression
(thanks to improved water cooling channels to combustion chambers and
sodium-cooled
valves) and a 2-stage intake manifold to enable very good power
output.
In
the diesel
side, there
are 3 engines - 82hp A160CDI, 109hp A180CDI and 140hp A200CDI. All of
them
are equipped with particle filter and comply with the strictest EU4
emission
regulation. They also employ second-generation common-rail injection to
enhance power, economy and quietness. Interestingly, the diesel engines
have dohc and 4 valves per cylinder, in contrast to the petrol engines.
Despite of the names, they all displaces 2.0 litres. The most powerful
A200CDI employs variable geometry turbine.
Transmission
include 5 and
6-speed manual as well as a new "Autotronic" CVT. It is the company’s
first
CVT. It has a manual override with 7 ratios, but most important, a
torque
converter with a lock-up clutch should avoid the "rubber band effect"
found
in ordinary CVTs.
As the turbo
version has
not yet arrived, the 136hp A200 engine mated with 5-speed manual
gearbox
is the one most journalists tested at launch. This engine is eager,
flexible
and frugal. The gearshift is short-throw and crisp. Like the rest of
the
car, the drivetrain combo is neither sporty nor lazy. It is just
refined,
efficient and highly enjoyable. Mercedes has found the right balance.
Unquestionably,
the second generation A-class will be another successful story, but
hopefully
this time it will have a smooth start. |
| The
above report was last updated on 18 Oct
2004. All Rights Reserved. |
Rollover crisis of the
original A-class
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In
November 1997,
when the first
generation A class was ready to deliver, a Swedish magazine rolled over
the A class under test, caused injuries to the testers. In then, they
were
performing "elk" test, which is commonly required in Sweden to prevent
the car from knocking down big deers suddenly appears in the road. When
they drove the A class at 60km/h and suddenly steered to avoid the
dummy
deer, the car simply rolled over and crashed.
This
incident
stunned the
world, newspaper and TV news reported it extensively, not only aroused
cancellation of orders, but seriously damaged Mercedes' world-wide
image
as the safest cars.
The
management
responded
quickly, added wider tyres, ESP (electronic stability programme),
lowered
ride height and further strengthened anti-roll bars. All were done
without
extra cost. As a result, the problem was solved. Meanwhile, it launched
an extensive advertising program in all media to rescue its image,
invited
the journalists who involve the overturned incident as well as ex-F1
champion
Niki Lauda to publicise how good the new car became. Mercedes lost
hundreds
of millions dollars in this crisis. Nevertheless, the A-class recovered
gradually in later years and eventually became Germany's best selling
car.
In the second
generation
A-class, Mercedes did further things to prevent rollover. See the main
report. |
| The
above report was last updated on 16 Oct
2004. All Rights Reserved. |
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