| Published
on 24
Jul 2013 |
All rights reserved.
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3-Series
Coupe becomes 4-Series. Is it different enough to justify the new name?
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The birth of
4-Series means the end of 3-Series Coupe, sadly. To understand why BMW
decided to split the car into a separate series, we have to look back
to its history. When the first 3-Series (E21) debuted in 1975, there
was no issue about how to distinguish the coupe and sedan because it
was available in 2-door body only. 4-door did not arrive until the
second generation (E30), but even then the only difference was the
number of doors. More differentiations came in E36 of 1990, when the
2-door got a faster windscreen, lower roof line and frameless windows
hence finally the "Coupe" moniker. Further differentiations were
introduced in the following E46 and E92 such that the 3-Series Coupe
now looked different enough to claim itself a separate model, although
underneath the sheet metal it was much the same as the sedan. Two
things triggered the ultimate divorce. First, Audi launched A5,
whose name and unique looks delivered a more upmarket image than either
the A4 or the 3-Series Coupe, which was still considered by many to be
the "3-Series 2-door". Second, BMW itself realized that by splitting
the coupes from their sedan roots, it can price them higher and earn
more profit. In this way, the 1, 3 and 5-Series are/will be derived
into 2, 4 and 6 series coupe respectively (BTW, 7er may also be derived
into 8-Series coupe if the Pininfarina Gran Lusso Coupe concept is
approved for production). This will inevitably decrease the sales of
3-Series, but total sales will increase, hopefully.
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The
result is a shape that looks more like a mini-6-Series than a 2-door
3-Series...
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To justify the separate name, the 4-Series differs from the 3-Series
more than ever in exterior design, if not the mechanical aspect. In
fact, with the exclusion of the shared bonnet, all body panels have
been reshaped to appear sleeker and more flowing. The new kidney grille
gets slimmer and more 3-dimensional. The front bumper gets rounder and
incorporates more aggressive intakes (although most area is actually
blocked out). The front fender is enhanced with inverted-L-shape air
extract, which looks elegant yet helps reducing aerodynamic drag. The
shoulders get broader to look sportier and accommodate wider tracks.
Speaking of tracks, you will be amazed to hear it is wider than the
sedan by 45 mm front and 80 mm rear. Meanwhile, the roof has been
lowered by as much as 67 mm, or 13 mm lower than the old coupe, while
ride height is reduced by 10 mm. The result is a shape that looks more
like a mini-6-Series than a 2-door 3-Series. In other words, it looks
stylish.
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The
interior remains common to the 3-Series in order to save costs.
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While exterior design has finally become a selling point of the coupe,
the interior remains common to the 3-Series in
order to save costs. Although the dashboard functions flawlessly and
the build quality is good, it looks and feels too ordinary for a
sporting model, lacking the exclusivity you would expect from its
exterior design. On the plus side, the cabin offers good accommodation
for a coupe of this size. The faster roof line might have reduced rear
headroom by 13 mm compared with the old coupe, but rear legroom is
boosted by the same amount. This mean the two individual rear seats
still offer enough room for normal size adults. It is a
genuine 4-seater, something Audi A5, Cadillac CTS Coupe and Infiniti
G37 Coupe cannot claim. As you can expect, the driver seat and driving
position are excellent. You sit 19 mm closer to the ground than in the
case of the sedan, so it feels adequately sporty.
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The
faster roof line reduces rear headroom by 13 mm, but rear legroom is
boosted by the same amount.
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Mechanical-wise, the 4-Series remains to be largely 3-Series. Its steel
monocoque chassis is 25 kg lighter than its predecessor's yet the front
structure is 60 percent stiffer, thanks to 2 additional braces
connected between the front subframe and the body. BMW did not reveal
its
torsional rigidity figure, but its 2-door body is unquestionably
stiffer than
the 3-Series'. In addition to the wider tracks, lower center of gravity
and stiffer springs and bushings, it should be more capable in
maneuvering. Like the sedan, adaptive dampers and variable-ratio
electrical power steering are optionally available together with the M
Sport package.
On the road, it drives exactly like a 3-Series sedan with slightly
sharper handling, better grip and tauter body control. The difference
is not huge, but enough for a coupe intended to be an everyday car. As
in the case of the 3-Series, it is well balanced, agile and eager to
steer, but the electrical power steering is a tad too light and
artificial for a
sporting machine. Naturally, the ride is firmer than the sedan. If the
most
aggressive 19-inch wheels and low-profile tires (225/40 front and
255/35 rear) are taken, it could be overly firm, failing to match the
suppleness of its predecessor. Fortunately, you can switch the adaptive
dampers to Comfort mode if you want relaxed cruising.
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It
drives exactly like a 3-Series sedan with slightly sharper handling,
better grip and tauter body control.
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The least worth mentioning aspect of the car is the range of engines,
because they come straight from the 3-Series. Initially, these include
the 184 hp 2.0 turbo diesel (420d), 245 hp 2.0 turbo petrol (428i) and
the range-topping 306 hp 3.0 straight-six turbo petrol (435i). Later on
they will be joined with 184 hp 2.0 turbo petrol (420i), 258 hp 3.0
turbo
diesel (430d) and 313 hp 3.0 sequential twin-turbo diesel (435d). All
of them are good engines, but the fact that they are no more powerful
than the equivalent 3-Series sedans is not so amusing, especially when
the 4-Series is pricier and supposed to be more performance-oriented.
In the case of 435i, the situation is even more embarrassing as its
engine is carried over from the last generation 335i
coupe. We used to be excited with the 335i because at that time it was
a
performance bargain. Now the same 0-60 mph time of 5.1 seconds (or 4.9
seconds for the excellent ZF 8-speed auto) is no longer that special.
It will be remembered for its silky and lag-free power delivery more
than outright performance. For sure, BMW is capable to extract more
firepower and a sportier exhaust note from the N55, as shown in the
M135i, but it would rather
leave those to the optional M Performance package, which won't be
cheap.
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435i
will be remembered for its silky and lag-free power delivery more than
outright performance.
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Is the 4-Series special enough to be worth the separate name? I don't
think so. Although it looks more stylish than ever, its underpinnings
are pure 3-Series stuffs, whereas the powertrain and chassis tuning is
too civilized. The 335i is now more like a laid-back luxury coupe than
a junior M3 (well, that should be M4 now). Having said that, in the
world of mid-price 4-seater coupes, the BMW is still the best
all-rounder. It offers a pretty shape, genuine 4-seat accommodation,
good build quality, good performance, refined powertrains and fine ride
and handling. No one else can quite match its completeness.
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Verdict:  |
| Published
on 29
Jan 2014 |
All rights reserved.
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4-Series Cabriolet (F33)
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One
of the few survivors of coupe-cabriolet.
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The fever of
coupe-cabriolet rose and fell quickly in the past decade. At the peak
we had no fewer than 17 coupe-cabriolets to chose
from, not including roadsters. Now that list is reduced to only 3. As
far as I can remember,
casualties include Volvo C70, Peugeot 207CC, 308CC, Ford Focus CC, Opel
Astra TwinTop, Tigra TwinTop, Renault Wind, Daihatsu Copen, Nissan
Micra C+C, Mitsubishi Colt CZC,
Lexus SC430, IS C, Chrysler 200 Convertible and Pontiac G6 Convertible.
Gone or hurt seriously together with them are their makers, i.e.
Heuliez, Pininfarina, Bertone and Karmann. One of the few survivors is
BMW 3-Series Cabriolet – okay, it should be called 4-Series Cabriolet
now. It escapes from the axe not because it found a better solution
than its rivals. No, the new car is just as heavy as it used to be,
carrying a massive 225 kg of extra burden compared with the equivalent
coupe. Its boot space is marginally larger than before, but at 220
liters with the roof stored or 370 liters with the roof up it is still
very compromised, uses space far less efficiently than a typical soft
top. The CC conversion also damages aesthetic considerably. It loses
the fast-angle C-pillar of the Coupe and adds a bulky boot.
So why does BMW stick with retractable metal roof? I suppose because it
is engineered and built in-house since the very beginning. It would be
painful to write off the investment (R&D and production equipment)
with just one generation built. After all, its sales wasn't bad enough
to declare surrender yet.
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It
carries a massive 225 kg of extra burden compared with the equivalent
coupe.
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As before, the metal roof consists of 3 pieces and takes a very
sophisticated mechanism to fold into the boot. Open or close is quick
enough at 20 seconds. Improved sound absorbing materials used on the
roof lining helps cutting interior noise by up to 2dB in high-speed
cruising, so it feels impressively refined with the roof up. When the
roof is opened, it doesn't manage buffeting as good as Mercedes E-class
Cabriolet, so you might need the optional wind blocker, which is
installed manually behind the front seats. It is not only inconvenient
to use but also looks ugly and renders the rear seats useless. Speaking
of rear seats, they are a little tighter than E-class'. Otherwise the
interior is just the same as other 3 and 4 series.
With extra reinforcement, the chassis feels stiff enough in coupe form.
BMW claims its rigidity is 40% up from the old car. Nevertheless, in
open form there is still noticeable scuttle shake riding on uneven
surfaces,
which hurts driving confidence. Meanwhile, the massive weight also
hurts its handling. You can never escape from the feel that the back
end carries a heavy load. It leans and understeers quite a lot more
than the coupe or anything we expected for BMW. Its steering feels
quite vague, hesitating a while before executing your command.
Admittedly, all these might sound normal for other makes, but if you
have driven the 4-Series Coupe or even the 3-Series sedan you can't
help feeling disappointing, because you know its ingredients can do
more.
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In
open form there is still noticeable scuttle shake riding on uneven
surfaces, which hurts driving confidence.
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Performance also suffers from the weight. Even though 435i Cabriolet
claims 0-60 mph in 5.2 seconds, it doesn't feel so quick. However, if
you chase for a relaxed and effortless open-air motoring, then the
combination of turbocharged straight-six and 8-speed auto will be a
perfect companion, as it delivers a smooth and flexible progress. You
will need to work harder on the lesser 428i (245hp 2.0
turbo) or 420d (184 hp 2.0 turbo diesel).
The 4-Series Cabriolet is a disappointment. Think what could have been
done if it was converted to soft top, knocking off 100 kilograms, and
if its chassis was strengthened further. Before then, Mercedes E-class
Cabriolet is still a better bet, especially after the recent facelift.
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| Verdict: |
| Published
on 18
May 2014 |
All rights reserved.
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BMW M4 (F82)
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Downgraded
from V8 to straight-6, can turbocharging make up the loss?
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The biggest news
about the new M3 is not its separation into M4 coupe and M3 sedan,
because while they look different their underpinnings are actually the
same. What made headlines is the switch from V8 to straight-6 power. At
first it sounds like back to basics, but think again, it is not that
simple. To understand the cause of the change we have to go back many
years ago…
The M3 has long been regarded as the definitive coupe you can buy with
reasonable money and use on daily basis. Even at the peak of
Japanese coupe boom (i.e. the early 1990s) the BMW remained the most
sensible choice if you looked for a coupe that was fast, fun to drive
yet practical to use. A lot of its charm came from the fabulous
straight-six I would say. No matter the 286 hp 3.0-liter, 321 hp
3.2-liter or 343 hp 3.25-liter motors that served the E36 and E46 era,
they were renowned for a high-revving manner, razor-sharp throttle
response and sonorous soundtrack that no one else at affordable
segments could quite rival. As a result, its sales skyrocketed, from
19,000 units of the four-cylinder first generation to 71,000 units of
E36 and then 86,000 units of E46. It went from a motorsport
homologation special to a big business.
However, when Audi RS4 and Mercedes C55 AMG brought V8 power into the
scene, the M3 had no choice but to respond with a 4.0-liter V8. Yes, it
successfully retained the high-revving manner and pushed performance
even further, but the E92 lost some agility due to the extra
strengthening and rubbers required to withstand the increased power.
Moreover, it also cost a lot more to buy. Even though BMW tried to
broaden its appeal with the introduction of sedan and convertible
bodies, its final sales figure declined to 65,000 units, way fewer than
the 100,000 units originally planned. A lesson was learnt: more means
fewer.
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Inevitably,
some of the high-revving sensation will be lost in the process...
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Naturally, reverting to 6-cylinder motor is the answer. The problem is,
you need
to turbocharge it to keep performance while meeting modern demands for
reduced fuel consumption and emission. Inevitably, some of the
high-revving sensation
will be lost in the process.
All previous M3 engines were bespoke design by the M-division. Unlike
them, the new car's S55B30 motor is derived from the mass production
3-liter straight-six turbo designated N55. Disappointingly, it retains
the latter's undersquare combustion chambers with 84 mm bore and 89.6
mm stroke, hence the same 2979 c.c. displacement. The cylinder head
accompanied with Bi-Vanos and Valvetronic mechanisms as well as direct
injection are carried over. The cylinder block is new though, as it
adopts close-deck design to improve rigidity. The M-division's
lightweight pistons and forged steel crankshaft are employed to reduce
rotational mass and raise rev limit to 7600 rpm – though that is no
match with the 8400 rpm limit of the old V8. The cylinder bore is
treated with twin-wire arc spray (like AMG 6.2-liter V8)
to reduce friction. Meanwhile, the single turbocharger of N55 is
replaced with 2 IHI turbos to pump more air into the combustion
chambers. They are not particularly large – in fact, smaller
than those used by the old 1-Series M – thus maximum boost pressure is
only 1.3 bar. They are closely coupled to the exhaust manifolds to
reduce lag. The compressed fresh air is then transferred to the
water-to-air intercooler, which is mounted at the top of the engine,
offset to the opposite side of the tilted engine. This ensures the
shortest possible air path thus reduces turbo lag.
The result is a remarkable 431 horsepower released from 5500 to 7300
rpm,
and a maximum torque of 406 pound-foot available from as
low as 1850 rpm to 5500 rpm. The former edges out the old V8 by 11 hp,
but what makes a huge difference is the thick mid-range torque, because
the old V8 managed only 295 lbft at 3900 rpm. The M3 and M4 can now
accelerate from 0-60 mph in 4 seconds flat if you opt for the M-DCT
gearbox, whereas its speed regulation can be lifted from the usual 155
mph to 174 mph if you tick the M driver pack. They are now convincingly
faster than Mercedes C63 AMG
and Audi RS5.
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Unlike
all the previous M3 engines, the S55B30 motor is derived from the mass
production N55...
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There are more indicators to its superiority. Nurburgring lap time, for
example, is claimed to be cut by 15 seconds from the old M3. Meanwhile,
fuel economy is boosted from a dismal 24 mpg to 34 mpg, while CO2
emission is drastically reduced from 285 to 194 grams each km. Needless
to say, part of the saving comes from the Efficiency mode of the
powertrain and the overdrive 7th.
Yes, the new turbo six does feel considerably stronger and more
flexible than the old V8 in the real world. For a high performance
turbocharged motor with over 140 horsepower per liter, its turbo lag is
remarkably subtle, though its throttle response is nowhere as quick as
its naturally aspirated predecessors. Its output feels strong from 2000
rpm and even spectacular from 3500 to 5500 rpm, where you can rely on
the superior mid-range torque to give sensational in-gear acceleration.
The engine revs to 7600 rpm without much resistance, but you won't be
rewarded with any extra punch as the torque curve tails off after 5500
rpm. Consequently, you tend to adopt a more relaxing driving style,
scaling back throttle and gearchange, relying solely on the mid-range
torque to do the job. This lack of encouragement and the aforementioned
soft throttle response mean the car is not as inspiring to drive as a
traditional M3 should, sadly.
The lack of aural thrills is another big problem. All previous M3s,
especially the V8, produced magical noises approaching the top end of
their spectrums. In contrast, the new turbo six sounds dull across the
rev range. At idle it
sounds almost like a turbo diesel, blame to the strange diesel clatter.
At full
throttle it is very loud but hardly musical. To mask the unattractive
noise BMW uses a sound synthesizer to play a V8 bass through the
speakers (seems that they do care about the loss of V8). Unfortunately
it sounds too much artificial. Purists should be displeased.
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The
engine revs to 7600 rpm without much resistance, but you won't be
rewarded with any extra punch or aural thrills...
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While the engine is a disappointment, the rest of the car is not. The
new ZF 6-speed manual gearbox shifts sweetly, especially with the
addition of automatic throttle blipping. The Getrag 7-speed M-DCT works
well as long as you leave it in the middle (Sport) setting. Just avoid
the Lazy and Harsh modes. The active M differential varies torque split
between the rear wheels to control under and oversteer. The brakes, a
traditional weak point of the M3, is sorted out with the use of larger
compound discs (380 mm front and 370 mm rear) and stronger calipers
(4-piston front and 2-piston rear). Moreover, if you are willing to pay
more, you can get an excellent set of Brembo carbon ceramic brakes.
The chassis also plays an important role. As before, the M4 is the only
car in its class that achieves perfect static balance (the actual
figure is 49.6:50.4 front-to-rear). Moreover, it manages to cut 83 kg
from the old M3, bringing its kerb weight back to the level of E46. As
the smaller engine contributes to only 10 kg reduction – a testament to
the lightweight design of the old V8, more savings come from the
extensive use of lightweight materials elsewhere. For example, the
bonnet and front fenders are made of aluminum. The roof panel (as
before) and boot lid frames are carbon-fiber reinforced plastic (CFRP),
while the boot lid skin is glass-fiber. This mean the only steel parts
remaining in the body shell are the rear fenders and doors. Under the
skin, the propeller shaft is now made of CFRP, ditto the U-shape front
suspension tower brace that stiffens the front structure and
contributes a lot to visual drama. At the suspension, all control arms
and wheel carriers are now made of forged aluminum, saving 8 kg.
In order to sharpen chassis response, the new M3/M4 has ditched the
rubber bushings connected between the chassis and suspension subframes.
A more predictable upgrade is the addition of adaptive dampers as
option. They are linked to the driver control system that allows you to
adjust chassis behaviour independent of the powertrain setting. There
are 3 modes: Comfort, Sport and Sport+, with the former designed for
relaxed driving and the latter destined to none other than glass-smooth
race tracks. Beside them there is an M-mode which allows you to save
your favourite combinations. These modes alter not only the suspension
hardness but also the response of the new electrical power steering, M
differential and stability control.
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Accelerate
out of a slow corner with too much enthusiasm, the turbos will spool up
and trigger a rush of power, sliding the tail suddenly...
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Thanks to the combined effect of reduced weight and rigidly mounted
suspension subframes, the M4 feels sharper and more agile than the old
car. The turn-in is ultra-sharp, thanks in no doubt to the electrical
power steering which is direct, precise and linearly weighted. It could
do with more feel, but it won't feel shame beside a Porsche 911.
The ride is definitely stiff – so stiff that not even Comfort mode can
bring too much comfort. However, the resultant rock-steady body control
and excellent balance let you attack corners with full confidence. The
massive Michelin Pilot Super Sport tires, measuring 255/35ZR19 front
and 275/35ZR19 rear, generate immense grip. The front-end bite is
extraordinary for an FR machine, resisting understeer masterfully. The
rear tires offer excellent traction and grip, too. Nevertheless, the
turbocharged engine has enough grunt to slide the rear rubbers at
anytime, anywhere should the driver do that deliberately. It plays
power drift just as fluently as any old M3s, allowing the driver to
control the slip angle with throttle. The progressive way the tires
break away means you have plenty of time and feedback to make
correction. That said, there are moments that need your caution: for
example, accelerate out of a slow corner with too much enthusiasm, the
turbos will spool up and trigger a rush of power, sliding the tail
suddenly. It is not difficult to bring it back to line, but it does
shock you in a way none of its naturally aspirated predecessors would.
That slight reservation means nothing when you consider its improved
agility and response. However, the new M4 fails to score top rating due
to its turbocharged straight-six. Its dull noise and loss of
ultra-sharp throttle response might be acceptable for a Jaguar or Audi,
but not a BMW M-car. Considering the high level of engagement its
predecessor brought, it is a big disappointment. Is it an inevitable
outcome of turbocharging? I doubt. When an AMG 5.5-liter twin-turbo V8
can make a thrilling noise, it means BMW's engineers did not do the
best job. Right now, Mercedes C63 AMG Coupe remains to be the most
engaging car in the class.
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| Verdict: |
| Published
on 25
May 2014 |
All rights reserved.
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4-Series Gran Coupe (F36)
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The
4-Series is supposed to be the 2-door, sportier and sleeker looking
version of the 3-Series, but why do you add 2 more doors to it and
raise its roof line a bit?
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Life looked simpler
and easier in the good old days. Until 15 years ago BMW was still
making limited number of product lines with clearly distinguished
purposes – the 3, 5 and 7-Series were saloons in different classes,
6-Series was a luxury coupe and Z3 / Z4 was a roadster. That’s all.
Today, its lineup is expanded to cover not only every number from 1 to
7-Series but also X1, X3, X4, X5 and X6.
Furthermore, more spin-offs are derived from each series.
These include the 3 and 5-Series GT (i.e. crossover between saloon and
MPV), and lately the 4 and 6-Series Gran Coupe (i.e. crossover between
saloon and coupe). I suspect in the near future it may expand further
to Shooting Brakes like Mercedes-Benz.
Inevitably, the more number of variants, the more their survival space
overlaps. This situation also happens at Audi, where A4 and A5
Sportback are
stealing sales from each other. In the case of BMW 3 and 4-Series, the
overlapping is even severe. While it is easy to understand the
differences between 3-Series saloon and 4-Series Coupe or Cabriolet, it
is not so easy to establish a case for the 3-Series GT or 4-Series Gran
Coupe. BMW might tell you the 3er GT is a larger, roomier and more
luggage-friendly kind of 3er, but doesn't that sound like a 5-Series
Touring?
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It
is not as sleek or as beautiful as BMW would lead you believe...
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The 4-Series is supposed to be the 2-door, sportier and sleeker looking
version of
the 3-Series, but why do you add 2 more doors to it and raise its roof
line
a bit to create the 4er GC? BMW would tell you the GC is still lower
and sleeker than the 3er saloon. Yes, but it is not as sleek or
as beautiful as BMW would lead you believe. Moreover, by adding a
hatchback
door and extra reinforcement to compensate the large opening, the
car is actually 80 kg heavier than the equivalent 3-Series saloon. This
mean the supposedly sportier car is actually
the slower, engine by engine. And
it affords less headroom, not least because of the 40 mm drop of roof
but also the pronounced header required by the hinges of tailgate. Rear
passengers over 5 ft 10 tall will find their heads rubbing against the
roof liner.
You might say BMW can dial up the turbo boost of its engines to get
more performance. Unfortunately, it sticks to the policy of common
engines, so all the 7 engines available – 143 hp 418d, 184hp 420d,
258hp 430d, 313hp 435d, 184hp 420i, 245hp 428i and 306hp 435i – are
indistinguishable from the saloon. Ditto the 6-speed manual and 8-speed
ZF automatic gearbox.
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Rear
passengers over 5 ft 10 tall will find their heads rubbing against the
roof liner.
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Unbelievably, the biggest advantage of the Gran Coupe over the 3-Series
is luggage carrying capability. Although both boots measure 480 liters,
the GC's liftback allows easier loading, and its 40/20/40-split rear
seats
may fold flat to expand load bay, which is good for placing bike or
surf boards. A 3-Series Touring swallows even more, but it won’t match
the 4-Series GC for looks.
Although the rear seats offer less headroom, legroom is
just as generous as the 3-Series, thanks to the same 2810 mm wheelbase.
I would prefer
its dashboard and trims to look more special, but
like other 4-Series models, the idea was rejected on the ground of
cost. This mean it has to settle with a slightly boring dash design and
a
perception of mass production build quality. Here, it is well beaten by
the new
Mercedes C-class.
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Frameless
windows means more road roar to be heard, but otherwise it drives
similar to the 3er.
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Just like other BMW coupes, the GC employs frameless windows to enhance
looks. This might be the reason why you can hear more road roar from
the tires. Otherwise, it drives similar to the 3-Series. The chassis
displays remarkable balance and grip. The steering is direct, precise
and nicely weighted. With the adaptive damping set to Sport mode, it
feels almost like a sports sedan. The GC employs slightly stiffer
suspension than the saloon. The difference is small, but you can feel
its extra agility – especially because you sit closer to the ground in
this car – as well as marginally harsher ride. Nevertheless, such a
slim difference might not justify the loss of rear seat accommodation
and acoustic refinement. Neither does its looks justify the price
premium of 10 percent. To me, the 3-Series Saloon is still the more
sensible buy, while image seekers should always choose the 4-Series
Coupe.
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| Verdict: |
Published
on 19
May 2016
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All rights reserved.
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M4 GTS
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Water
injection injects a new lease of life into the most hardcore 4-Series.
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Remember the last
generation M3 GTS? It was the hardcore, track-focused version of M3
Coupe, having an extra 30 horsepower and 50 kg less weight than the
standard car. Now the GTS badge returns with M4. Headline news is 500
horsepower from the same 3-liter twin-turbo straight-six. That's a
significant increase from the standard car's 431 hp. Meanwhile, peak
torque is lifted from 406 to 442 lbft at 4000-5500 rpm. How can it
achieve that? Surprisingly simple, by using water injection. BMW said
this is the first production road car to employ this motorsport
technology. In the M4 GTS, a 5-liter water tank is added under the boot
floor. Water spray is injected to the intake manifolds (after
intercooler) at 10 bar, then it is evaporated, cools the air intake
from 70°C to 45°C, makes the air denser while increases
resistance to knock. The latter effect allows the use of 1.5 bar turbo
boost pressure instead of 1.3 bar, which accounts for the increased
output. Since there is no modification to the engine internals, the
straight-six's maximum rev is still bounded at 7600 rpm, while max
power is released at 6250 rpm. M-power hardcores could be a bit
disappointed.
However, its performance is unlikely to disappoint. The GTS lapped
Nurburgring in 7 minutes and 28 seconds, slotting between a Porsche 991
GT3 (7:25) and new 991.2 Carrera S turbo (7:34). On the straight, it
would do 0-60 mph in 3.7 seconds or three-tenths faster than the
standard M4. The electronic speed regulation is lifted from 174 to 190
mph.
Unsurprisingly, the car is equipped with 7-speed M-DCT exclusively
because manual gearbox could not match its performance requirement.
Power is put down to the road through track-oriented Michelin Pilot
Sport Cup 2 rubbers (like 911 GT3 RS), which are 10 mm wider and, in
case of rear ones, an inch larger in diameter. They are wrapped around
bespoke forged alloy wheels with 10-pointed star design.
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Cabin
is obviously designed to save weight.
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At 1510 kg on DIN scale, the new GTS is only 27 kg lighter than the
standard M4 DCT. This is not too much of surprise because the M4
already employs quite a lot of aluminum and carbon-fiber in its
construction. The GTS employs even more carbon-fiber, such as the
bonnet (vs aluminum in M4) and boot lid (vs glassfiber), although the
steel door shells seem to be carried over for the sake of crash
protection (probably too costly to re-engineer and certify). Of course,
all the extra aero kits, such as front splitter, diffusers and that
signature rear spoiler, are also made of carbon-fiber. The titanium
exhaust muffler saves 7 kilograms. However, most weight saving seems to
come from the cabin. The carbon-fiber racing buckets weigh half as much
as the standard items on M4. The center console and door panels are
lightened (like Porsche, door handles are replaced with fabric pull
bands). The rear seats are ditched and replaced with a glass-fiber
panel. The orange roll bar spotted in this picture comes with Clubsport
package, which also includes racing harnesses and a fire extinguisher.
Order this pack if you go track racing.
In the chassis, there are some modifications. The suspensions skip
adaptive dampers but are now served with coil-over springs/dampers,
whose compression, rebound and ride height are adjustable if you don't
mind to use a spanner to do the dirty work. Needless to say, the
suspension tuning is different, with 60 percent stiffer springs,
thicker anti-roll bars and more negative camber. The electrical power
steering is basically unchanged except a software retune, but the
steering column is now mounted rigidly without rubber bushings to
enhance feedback. Lastly but not least, the steel brakes are replaced
with carbon-ceramic items to allow lap after lap of abuse.
Outside, the front splitter and rear spoiler are both adjustable (again
by tools). In their most aggressive settings, the car generates 12 kg
and 40 kg downforce at the front and rear axle respectively when
travelling at 124 mph. Not quite the league of Ferrari or 911 GT3 RS
though.
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The
straight-six screams louder and angrier. In curves, the GTS is a much
different animal...
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Like the last generation M3 GTS, the M4 GTS is both exclusive and
expensive. Only 700 units will be built, each charges £120,000
before options, which matches an Audi R8 V10, Porsche 911 Turbo, 911
GT3 RS or Aston Martin V12 Vantage S. The same money can buy you 2
standard M4s. It seems a bit mad to me.
So how does it feel on road? If you are disappointed with the M4 like
us, the first sign of GTS should be positive – its straight-six screams
louder and angrier than the standard car, thanks to that crackling
exhaust note and reduced sound insulation. It feels stronger, too, but
don’t think it can recapture the soul of traditional M-power when
chasing redline, because its power delivery is still typically
turbocharged. It doesn't have much turbo lag to overcome, but it is not
enthusiastic to rev beyond its rather low power peak, something the new
911 Carrera S does better.
Fortunately, in curves the GTS is a much different animal. Its passive
suspension is very firm on road, but it keeps body movement to the
minimum. More important, the Cup tires generate massive grip. On the
standard M4, the engine’s tremendous torque could easily unstick the
rear rubbers and run into oversteer, so its handling is sometimes
nervous. In contrast, the M4 GTS not only grips harder but it remains
superbly balanced – it resists both understeer and oversteer
remarkably, a rare achievement for an FR. You can exploit the car much
harder yet with more confidence. The steering also feels more direct
and communicative than the standard helm. At the limit, the chassis
runs into either sides of neutral with a progressive manner, so it is a
perfect tool for track days.
Ultimately, the M4 GTS cannot quite match a Porsche 911 GT3 RS, or to
lesser extent the cheaper GT3, which offers noticeably more traction, a
bit better steering feel, brake feel and a much much sweeter engine.
The BMW’s stiff and non-adjustable ride is also more compromised for
road use. And would you pay more money than those hardcore Porsches for
an M4 with wings? That’s why its production volume has to be very
limited.
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| Verdict: |
Published
on 6
Jun 2017
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All rights reserved.
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M4 CS
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£90K
is a lot of money for an M4. What does it bring you?
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I am a little regret for
overlooking the M4 Competition package launched last year. Generally
speaking, I don’t bother to spend time on something called “pack”,
because only fools would market a sizeable upgrade as “pack”. Somehow,
the Competition pack does improve the M4 quite a lot, mainly because
the chassis setup of the standard car left a lot to be desired. Its
potential had not been unlocked until the Competition pack brought
stiffer suspension springs, dampers and anti-roll bars, and has its
electronics recalibrated (steering, stability control, active M
differential and drive modes). The result is sharper handling and a
more forgiving manner at the limit. The pack also brought an extra 19
horsepower to a total of 450, cutting 0-60 by a tenth.
In the UK market, a standard M4 DCT now costs £60K. The
Competition pack adds £5K on that, while the track-oriented,
500-horsepower GTS tops out at an eye-popping £120K. Apparently,
there is space for another model sitting in the gulf between
Competition pack and GTS, and here comes the £89K M4 CS. BMW did
not explain what CS stands for, but I guess Club Sport could be an
answer. It will be more hardcore than the Competition pack, but cheaper
and more usable on the road than GTS. Not just M4, but the M3 and M2
will get CS treatment as well soon.
Although the car is expected to be relatively rare – about 1000 units
will be made per annum for the next 2 years – nearly £90K is a
lot of money for a coupe based on mass production design, i.e. the 4
and 3-series. For comparison, a Mercedes-AMG C63 S costs “only”
£70K even though it has a V8 engine to shine, while the new Audi
RS5 Quattro asks for only £63K. Even a Porsche 911 Carrera S
demands only £87K. How can the M4 CS justify so much money?
The answer is more grunt, less weight and retuned chassis.
Hardware-wise, the 3-liter twin-turbo straight-six is unchanged, but
its ECU is remapped to release another 10 hp over the Competition for a
total of 460 hp. Most important, its maximum torque is lifted by 37
lbft to 442 lbft, equaling the GTS despite the lack of water injection
technology. Although BMW people decline to talk about specific changes,
it
seems to me that only a slight increase of turbo boost could account
for this extra grunt, which is noticeable in the mid-range and gives
the car better in-gear acceleration. The car now feels as fast as
anything in the class, C63 S and Alfa Giulia QF included. Meanwhile,
the engine sound is also a tad better, louder (thanks to less sound
deadening) and more guttural, even though it is no match for AMG V8 or
the titanium-exhaust GTS.
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Sharper,
faster, more communicative and predictable to exploit... but it ain't a
911.
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The CS employs only M-DCT gearbox in order to achieve a Nurburgring lap
time of 7:38. Although BMW is one of the first to employ dual-clutch
gearbox, it is no longer the leader. The alternatives found on
Porsche and Audi are simply better. The M-DCT is still very fast in its
sportiest mode, but it comes with a violent manner you won’t find in
its
rivals.
The CS is 32 kg lighter than the standard M4 DCT. It seeks weight
saving from a carbon-fiber bonnet, diffusers and rear spoiler, as well
as manually-adjustable sport seats, Spartan door panels (with GT3-style
fabric door pulls), reduced sound insulation, downgraded climate
control, audio and infotainment systems. However, it keeps the
essential air-con and the rear seat.
Its suspension setup is the same as the Competition, which means
stiffer springs, anti-roll bars and dampers, but it is fitted
with lighter forged alloy wheels and wider, stickier Michelin Pilot
Sport Cup 2 tires like the GTS. The latter has a decisive influence to
its handling behavior. BMW tailors the adaptive dampers, stability
control, power steering and M differential software to suit the new
rubbers. On the road, it feels better than the Competition pack again,
with more roadholding, flatter cornering, quicker turn-in and more
progressive transition into oversteer at the limit. The stickier front
rubbers clear the slight hesitation of the electric power steering,
resulting in
a more connected feel and giving you far more confidence to exploit the
chassis. Meanwhile, the suspension still rides over bumps competently.
At attacking speed, vertical motion is better controlled, so it
actually feels more composed.
The weakest link of the car is braking. The standard M4 is already weak
on this aspect (a BMW tradition). The CS keeps its cast iron discs with
4-pot calipers up front and 2-pot at the rear. After a couple of laps
of abuse, its pedal softens and stopping power fades. Carbon-ceramic
brakes are available, but need extra cash, which is unreasonable for a
£90K M4. Yes, the M4 CS is easily the best M4 for road use, being
sharper, faster yet more communicative and more predictable to exploit,
but it is no replacement for a dedicated sports car like Porsche 911.
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| Verdict: |
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