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In the past 50 years,
Mercedes-Benz S-class was widely recognized as the best series
production luxury car in the world. Without this car, Mercedes would
not have been considered as the best luxury car manufacturer,
especially now its sales volume is eclipsed by BMW. The point is, no
one delivers luxury, comfort and safety as good and as consistently as
the big Mercedes.
How far the history of S-class goes back is always debatable. Mercedes
started using the name "S-class" in 1972 (on series W116), but the line
obviously had been existing long before that. Because the early
cars got only model names, say, 220 or 250SE, it is impossible to tell
whether they are S-class models from names. It was not until 1993 that
the new corporate nomenclature (model designation started from C, E or
S and followed by 3 digits denoting engine capacity) could clearly
identify the model class.
Mercedes itself said the earliest S-class was W187 series (born 1951).
According to wikipedia (well, not always a reliable source) the S-class
started from W180 (1954). In my opinion, neither deserved the S-class
title. While you may trace its roots to these cars, they were not good
and distinctive enough to be seen as a top notch luxury car, because
they were mechanically and visually close to the other offerings from
Mercedes-Benz then. If S-class means the classiest production model of
Mercedes, then the first S-class has to be W111/W112 from 1959.
Which
luxury brand dominated the late 1950s ? Not Mercedes-Benz of course. It
was Cadillac. As you can see from our article of the 1957 Cadillac
Eldorado Brougham and the 1959 Cadillac, the
American luxury brand was leading the fashion and technology of the
time thanks to the wealth of General Motors. Born in 1959, Mercedes
W111 and W112 series could not escape from the Cadillac's influence,
most notably its "tailfins" and self-leveling air suspension. However,
it also got some technological breakthroughs, such as the world's first
safety chassis (a rigid passenger cell sandwiched between front and
rear crumple zones) and the first all-wheel disc brakes in the class.
Besides, its 4-speed automatic transmission, Bosch mechanical fuel
injection, all independent suspensions (by double-wishbones up front
and low-pivot swing axle at the rear) and dual-circuit braking system
were also considered advanced features then.
The W111 series was
the mass market version. It was powered by Mercedes' well-proven SOHC
straight-six engine displacing 2.2 liters. Fitted with carburetors it
was called 220 or 220S, while fuel-injected version was called 220SE.
Both saloon and coupe version were offered. Autocar magazine tested a
220SE Coupe in 1961 and was impressed by its overall completeness, no
matter speed, roadholding, ride, safety, comfort or refinement. The
120hp car achieved a two-way average of 106 mph in the test,
respectable for a large car.
W112 was the luxurious version of W111. Apart from more chromed
features and luxury equipment (including air suspensions, all-round
disc brakes and power steering), it was available with a 100mm longer
wheelbase version. Moreover, it was powered exclusively by a 185hp
3.0-liter fuel-injected straight-six, which was the mass production and
alloy-block version of the one serving 300SL.
The resultant 300SE was good for 114 mph and 0-60 in just over 10
seconds.
The W111 / W112 was probably not yet the best luxury car in the world.
However, from its advanced technology and overall refinement it had
already shown a promising future.
Having
seen it in person, I think the W108/W109 series from 1965-72 is the
most graceful looking S-class of all (although W126 is close). On
the one hand, it retains the classical elements of traditional
Mercedes-Benz designs, such as a round bonnet, a prominent radiator
grille
and a lot of chromes. On the
other hand it introduced a modern shape that is characterized by clean
lines, large glass area and rounded corners. In other words, it
combined the best of both worlds. This remarkably
refined design was penned by Paul Bracq, who had a
lot of influence to Mercedes in the 1960s and BMW in the 1970s.
Mechanically, W108/109 was a development from the outgoing
generation. The basic design of suspensions and powertrains were
carried over, but the six-cylinder engine was enlarged from 2.2 to
2.5 liters and later on 2.8 liters. The latter came with Bosch
D-Jetronic
electronic fuel injection, which was a progress from the previous
mechanical injection. The 2.8-liter engine powered not only 280SE, but
also the range-topping 300SEL since the old 3.0-liter engine retired in
1967. Such embarrassing situation continued until 1969 when Mercedes
finally developed a new V8 engine. Destined primarily
to the USA market, it appeared in two forms: 3.5-liter 200hp or
4.5-liter 230hp. Performance and image were greatly enhanced.
As before, W108 was
the mass market version, while W109 was luxurious version with 100mm
longer
wheelbase and air suspensions. The W108 models were called 250S, 250SE,
280S or 280SE depending on engines. Body styles included sedan, coupe
and convertible. All W109 models were called 300SEL regardless of
engine.
Interestingly, 3.5-liter and 4.5-liter cars were never called 350SE or
450SEL etc., but 280SE 3.5, 280SE 4.5, 300SEL 3.5 and 300SEL 4.5.
Also worth noting is the high-performance 300SEL 6.3, which was fitted
with a mega V8 from the 600 limousine. It will be covered by
a separate article.
Thanks to its solid build quality, superb mechanical refinement and
elegant yet restrained style, the W108/109 S-class overtook the
American Cadillac and Lincoln to be the world's best luxury car. Since
then it never looked back.
This
S-class flooded the streets in my childhood. Nevertheless, I do not
have very fond memory of it, blame to its unrefined design. The W116
was born at a time new safety regulations getting effective. This
demanded plastic bumpers and rubber side stripes. Unfortunately, like
everyone else, Mercedes had not masterminded the art of integrating
these safety features into the body shell, so they looked ill-fitted
and at odds to the rest of the car.
Style-wise, the W116 was a brave (an unsuccessful) attempt for
modernization. Its body shell was widened and lowered. The radiator
grille evolved shorter and wider, while traditional circular headlights
were replaced with two large rectangular ones with signal lamps
integrated. Weight went up by around 100 kg, mostly due to improved
safety. To enhance crash protection, the cabin section was made
stiffer, and further research improved the progressive crumpling of the
front and rear crumple zones. In the cabin, collapsible steering wheel,
recessed switches and padded surfaces reduce the level of injury in
collision. Fuel tank was relocated from the tail to above the rear
axle. These features made the S-class the safest car in the world.
Moreover, in its final year, it introduced the world's first ABS
anti-lock brake system.
The chassis was a big departure from the previous generation. While the
front double-wishbone setup sounds similar, it got anti-dive geometry
and zero Kingpin offset (i.e. the steering axis falls onto the center
of tire contact patch). The latter improved its steering response and
reduced kickback a lot. At the rear, the low-pivot swing axles finally
became history, as they were replaced with semi-trailing arms. This
tamed the oversteer of its predecessor, making its handling safer and
more predictable.
In the powertrain
side, the 2.8-liter straight-six of 280SE/SEL became twin-cam and
delivered an impressive 185hp (up 25hp). V8 models finally got proper
names – 350SE/SEL and 450SE/SEL. They were good for 200hp and 225hp
respectively, more or less the same as the ones introduced late in the
life of the previous generation. The automatic transmissions now got
torque converter instead of the previous fluid coupling for enhanced
smoothness.
Autocar tested both 280SE and 450SEL. They topped 125 mph and 134 mph
respectively, and accelerated from rest to 60 mph in 9.7 and 9.1
seconds respectively. The 280SE was praised for sweet revving engine,
good handling and ride. Performance of 450SEL was disappointing, partly
due to the power-sipping 3-speed automatic (lesser models used 4-speed
auto), partly due to its extra weight. However, the British magazine
praised it for refined ride, responsive handling that belied its size
and superb power steering. The latter was light yet quick and free of
kickback. No wonder 450SE/SEL was crowned European Car of the Year in
1974.
Like the previous generation, W116 was offered with a high-performance
model, 450SEL 6.9. This will be dealt with a separate
article.
With
a total sales of nearly 900,000 units (including sedan and coupe), W126
is by far the best selling S-class of all. It also had the longest life
(12 years). If not the best of the best, how could it be so successful
?
A couple of things mark W126 out of other S-class series. The first is
a timeless design. Most cars age within a few years. Good designs may
manage 20 years. But the W126 seems never age. Even today, 30 years
after its debut, it still looks as handsome and elegant as before. A
key contribution is the way it treated bumpers and side skirts, making
them working in harmony with the rest of the body. However, most
important is it did everything so right. The transition from one plane
to another is smooth and flawless. The integration of features into the
car approaches perfection. The only thing prevents it from matching
W108 is the lack of classical features, which made it less special from
modern eyes. That said, give it another 20 years and car collectors
then may have different view.
Another thing marks the W126 out is the sense of solidity it delivers.
This can be seen externally, of course, but the feel gets stronger once
you have sat inside. From its structure and build quality, this S-class
feels incredibly solid. It is void of the complication and
unreliability of subsequent S-classes, just gives you a very dependable
feel.
The chassis of W126 was an evolution from the previous generation. This
mean it continued to employ semi-trailing arms as rear suspensions. The
biggest advancement was aerodynamics (coefficient of drag lowered from
0.41 to 0.36) and weight reduction. They contributed to a 10-percent
reduction of fuel consumption. Besides, more safety features were
introduced to keep it at the forefront of safety, for example, air
bags, seatbelt pretensioners and the standard fitment of ABS.
At launch, it
offered 3 choices of engines: the carried over 185hp 2.8 dohc
straight-six (280SE/SEL), new 218hp 3.8-liter sohc V8 (380SE/SEL) and
240hp 5.0-liter sohc V8 (500SE/SEL). The V8s were developed from the
old 3.5 and 4.5-liter unit respectively, but with capacity increased
and changed to alloy block to save weight. 4-speed automatic
transmission became standard on most models, and now they were
computer-controlled. They provided two shift patterns, Sport and
Economy, and shift points were adaptive to driving conditions.
During its long life, the S-class was facelifted once and got engine
updates many times. The 3.8 V8 was superseded with 4.2-liter unit
(420SE/SEL). The 2.8 engine was substituted by 2.6 and 3.0-liter sohc
sixes. Following the introduction of 5.6-liter V8 in 1985, 560SEL
became the flagship model. In Europe it was good for 300hp and 155 mph,
although Autocar thought it was not as accomplished as BMW 750i, which
was V12-powered.
On the road, W126 was praised for well-weighted power steering,
excellent high-speed stability and a nimble handling for its
size. Its semi-trailing arm suspensions made it an inherent
understeerer, but by applying power it could be turned into
progressive power slide. On the downside, its ride was
slightly too firm for a luxury car (I can confirm this, as I had a
couple of rides in the car), and both wind and road noises were not
very well insulated from the cabin. Such a combination of handling and
ride characteristic was quite surprising.
W140
showed how things could go wrong if you pursue luxury, quality, power
and everything at all costs. It was born when Lexus LS400
and Infiniti Q45 started challenging the German at the top luxury
segment. To fend off the competition, Mercedes spent enormous money to
develop W140. It made the car much larger than the competition, gave it
a
modernized look (inspired by the 1989 SL-class), all-new suspensions
(subframe-mounted double-wishbones up front; multi-link setup at the
rear), a new 4-valve engine family (231hp 3.2 straight-six, 286hp 4.2
V8 and 326hp 5.0 V8) and even a 6.0-liter 48-valve V12 good for 408 hp.
The latter was a response to BMW's V12, and overwhelmed it easily.
Besides, the W140 got many luxury features not available to the class,
such as double glazing
windows, electric doors and boot lid closing, electric folding door
mirrors and speed-sensitive power steering. As a result, it
weighed 400 kg more than its predecessor, hampering its
performance and fuel economy. Moreover, it became extremely expensive,
so
it managed only half the sales of W126 during its 7 years life
span. The project resulted in loss.
However, it is
undeniable that the W140 was the world's best luxury car at the time.
Especially in the form of 600SEL, it was powerful and quick (0-60 mph
was possible in 6.7 seconds), spacious, comfortable and refined. Noise
suppression and ride quality were not as good as Lexus, but the big
Mercedes had better handling, a surprising triumph considering its size
and weight. The over-engineering perfected most areas. As long as
buyers could afford larger engines and the resultant fuel bills,
nothing could quite match the S-class in the world of luxury motoring.
On the other hand, the press thought it was simply too much - too big,
too expensive and too environmental unfriendly. It did not beat its
rivals squarely and fairly, just overwhelmed them with more mass, more
sophistication and more money. This negative image would not be
overcome until the next generation arrived.
It should be noted that the model designations of S-class were changed
in 1993. Following the new corporate nomenclature, 300SE, 400SE, 500SE
and 600SEL were renamed to S320, S420, S500 and S600 respectively.
Having
learned a lesson, the next generation S-class, W220, was designed to
be lighter, smarter and less costly to build. Its body shell was
smaller in all dimensions, matching the class norm. This, together with
using more high-strength steel, all-alloy engines and discarding the
double-glazing windows, made the car 300 kg lighter than its
predecessor. Besides, the chassis was 40% more rigid than the old car,
while a sleeker shape returned a much lower drag coefficient at 0.27.
As a result, the W220 could use smaller engines to achieve the same
performance. For example, the new S320 was as fast as the outgoing
S420, while S500 was faster than the old S600. This mean it was much
more frugal than the old car.
The W220 was being developed at a time Mercedes started getting radical
- both in design and development process - under the leadership of its
CEO Jurgen Schrempp. Its sleek new look appeared to be much younger
than ever, but many radical elements, such as the peanut-shaped
headlights, round bumper intakes and slim radiator grille, aged quickly
over time. This mean it looks rather outdated today. The build quality
and reliability also took a nose dive as Schrempp drove for
cost-effective engineering. The W220 used cheaper materials in its
cabin and its development and testing process was shortened. The latter
resulted in many electronics glitches. This was not helped by its vast
extension of electronic technologies, e.g. AIRmatic adaptive air
suspensions,
CCS cylinder cut-off (on 5.0-liter V8), Distronic and Speedtronic
computer cruise control, ESP stability control, BAS brake assist,
integrated infotainment system...
To standardize engine production and save costs, W220
employed a 90-degree V6 and V8 family. The former needed a balancer
shaft to cancel first order vibration. Mercedes believed 4 valves per
cylinder could not comply with the cold-start emission requirements of
EU 2004 emission standard (which was proved to be wrong), so these
engine reverted to SOHC 3 valves per cylinder. The resultant power loss
was largely compensated by using dual ignition, variable
intake manifolds and intake variable valve timing. Broader torque
delivery actually made the cars perform better in real world. At the
top of the range, a new 367hp 5.8-liter V12 was developed for S600,
again based on the SOHC 3-valve design of the V6 / V8.
In 2002, the V12 was added with twin-turbo, boosting output to an
incredible 500hp. The new S600, equipped with Active Body Control
suspensions,
became an Autobahn rocket. Meanwhile, AMG joined the party with two
fast S-class, S55 (powered by 500hp 5.5 supercharged V8) and S65 (612hp
6.0 twin-turbo V12). They had sportier handling and coarser ride than
the standard car. However, the regular W220 was never short of talent
in handling. The switch from recirculating ball to rack-and-pinion
steering improved its steering feel and precision a lot, while adaptive
suspensions (AIRmatic or ABC) improved its body control without
sacrificing ride quality. It was considered to be a good compromise
between handling and comfort.
Commercially, the W220 was more successful than W140. However, its
downgraded reliability and build quality cost Mercedes heavily in
reputation.
Mercedes learned from
mistakes in the past. After the over-engineered W140 and the
underdeveloped W220, it finally hit the right balance with W221. The
new S-class is sized between the two, offers enormous interior space
yet weighs only 65 kg more than W220, thanks partly to aluminum hood,
trunk lid, doors and front fenders. It keeps a sleek profile and low
drag, but the detailed design is far more graceful than the old car.
Inside, the new S-class has its materials and build quality vastly
improved, getting back to the top of the game. High-tech features like
LCD instrument panel, Night View infrared camera and Pre-Safe safety
system distinguished it from rivals. Same go for the super-comfortable
front chairs, which come with heating, cooling, massagers and side
bolsters that inflate automatically during hard cornering to hold the
occupants firmly in place. Besides, the cabin is remarkably quiet and
free from road intrusions.
The chassis is an evolution of the outgoing series. The suspension
geometry, adaptive air suspensions and steering were refined without
big changes. S600 continues to employ active body control. Again, the
S-class does not steer as well as BMW 7-series, but it provides a
smoother and quieter ride, thus is unquestionably the better luxury car.
The twin-turbo V12 of S600 is largely the same as before,
only got a slight, 17hp boost in output. Other engines were renewed.
The 90-degree V6 and V8 got 4-valve heads, dual continuous variable
valve timing as well as extra capacity, boosting output considerably.
Furthermore, the automatic gearbox was upgraded from 5 to 7-speed (S600
kept the 5-speeder as the 7G-Tronic could not withstand its tremendous
torque). As a result, all S-class models bar the S600 are significantly
quicker than their predecessors. AMG models include S63 and S65, the
former got an all-new 525hp 6.2-liter 32-valve V8, while the latter
carried over the old engine.
By the turn of the decade, Mercedes focused its development to the
green side. In Europe, more and more sales fell to its ever maturing V6
turbo diesel. Meanwhile, Mercedes also introduced S400 Hybrid (powered
by V6 plus a small electric motor integral with transmission) as an
attempt to narrow the gap from Lexus. In 2010, the V6 and V8 family was
overhauled to achieve a 25 percent reduction in emission and fuel
consumption. The 90-degree V6 was replaced with a 60-degree V6 with
direct injection, auto start-stop and other fuel-saving designs. The
new V8 got the same technology, plus a reduction in capacity and
addition of twin-turbocharger. The result is even better performance,
drivability yet more environmental friendly. AMG's 6.2 V8 was also
replaced with a twin-turbo 5.5 V8, with similar improvements.
Although the W221 is still in production at the time of writing, we can
conclude that it is a better car than its two predecessors. However, as
the S-class is facing tougher competition than ever, it seems difficult
to repeat the success of W126 in the foreseeing future.
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