Mercedes-AMG C 63 S 2015 Track Test Review

Mercedes-Benz rewrote the rulebook for mid-size luxury sports sedans with the outgoing C 63 AMG sedan, which arrived Down Under in March 2008 with a bellowing 336kW/600Nm 6.2-litre V8 that belted it to 100km/h in 4.5 seconds. Yet it cost just under $140,000 -- $21K less than the 270kW C 55 it replaced and $17K less than even BMW's cracking M3 Coupe of the day. Naturally enough, it sold like hotcakes, easily outselling chief rivals like the new M3 sedan, Audi RS 4, Lexus IS F and even HSV's cheaper V8 Commodore-based line-up. Now, the replacement for AMG's best-seller sets more benchmarks, and it's no wonder the local waiting list stretches well into next year.

The meteoric success of Mercedes-Benz's performance brand in Australia is well documented. More AMGs are bought per head of population than anywhere else in the world, and a big chunk of them are C 63s.

The outgoing model found more than 40,000 buyers globally and about 3000 Down Under, making it AMG's most popular model ever and helping the Affalterbach brand sell about as many vehicles as Porsche so far here this year. That's no mean feat since Porsche sales are up more than 60 per cent in 2015.

But if think thought up to 500 buyers a year for a circa-$150K V8 German sedan is a lot, all 300 examples of the new C 63 due here this year are already spoken for, and Benz says the 700 or so it has secured for 2016 will sell quickly.

Why? Because as good as the old model was, the first all-new C 63 in seven years – based on the same new rear-drive MRA platform that debuted underneath Merc's lauded new C-Class -- is better in every respect, including power, torque, acceleration, efficiency, dynamics, space, safety and standard equipment.

It's also produced in standard and high-output S forms (only the latter is available here, for now) plus limited Edition 1 guise, again offered in both sedan and wagon body styles (with a new coupe to come next year), and cheaper than the final 507 Edition of the outgoing W204 C 63.

As we learned in February, when Australian pricing and specs were announced before we drove it at the international launch, the C 63 S sedan costs $154,510 – undercutting its closest rival in the M3 sedan by about $1500 -- while the Estate is $2500 more at $157,010 and the Edition 1 adds another $7900 in either body style.

And while competitors like the M3 move to turbocharged 3.0-litre six-cylinder power, with Audi's next RS 4 and newcomers like the Jaguar XE SVR and Alfa Romeo Giulia QV likely to follow, the C 63 sticks with bent eight firepower.

Yes, the old C 63's thumping atmo 6.2 V8 is gone, replaced by a downsized twin-turbo 4.0-litre that's related to the AMG GT S supercar's V8 and produces the same 375kW of peak power (2kW more than the old C 63 Edition 507) but lacks its dry sump.

The new C 63 S does, however, deliver 50Nm more peak torque than the GT S, with a brawny 700Nm of twist on tap anywhere between 1750 and 4500rpm, which is 90Nm more than the 507 and also a big step up on the standard 350kW/650Nm C 63 not sold here.

Mercedes says that's enough for the 1655kg C 63 S to hit 100km/h in a supercar-scaring four seconds flat, which for the record is half a second quicker than before and a tenth quicker than the less powerful but lighter M3 (317kW/550Nm, 1560kg auto). And the 1725kg wagon is as quick as the M3 sedan.

In fact, the C 63 hits 100km/h as fast as the standard AMG GT not sold here and just two-tenths later than the GT S, which is 85kg lighter at 1570kg and can stretch out to 310km/h while the C 63 is limited to 250km/h.

We couldn't tell the difference in acceleration between the two at Mount Panorama this week, when Mercedes staged the biggest and most expensive AMG customer event ever seen in Australia to launch both the GT S and new C 63 S.

Both cars felt equally quick at Bathurst – not Porsche 911 Turbo quick, but quick enough to compress the padding in the single-piece bucket seats and overpower my neck muscles with a helmet on, as the sedan's seven-speed automatic transmission (AMG's SPEEDSHIFT MCT with wet start-off clutch instead of a torque converter) snapped through the gears as rapidly as the coupe's seven-speed dual-clutch auto.

Of course they were both fast too; fast enough to get frighteningly light at full noise over the hill going up Mountain Straight, and to hit 270km/h on Conrod Straight. At least, the GT S did with Mick Doohan at the wheel; all the AMGs we drove were manually speed-limited to 240km/h, which we hit well before The Chase in fifth gear in both cars.

Indeed, in our limited time on track in near-freezing conditions, the C-Class felt as rapid as AMG's new supercar, launching off the line with all the ferocity of the old atmo 6.2, setting off the ESP warning lights in its midrange as easily as the E 63's biturbo 5.5, and spinning hard and free all the way to 7000rpm and beyond.

Also defying everything we knew about turbo engines is the C 63's complete lack of lag. Ever. Plant your right clog from any revs at any speed and the force-fed eight reacts just as instantly as any traditional high-performance big-bore engine we've ever thrashed.

And its ferocious performance is accompanied at all times by the glorious, hairy-chested growl of a proper German V8, and the icing on the cake is an overrun pop and crackle when you get off the loud pedal.

There's no doubt its unrelenting, sometimes overwhelming enthusiasm makes AMG's M177 V8 a match – in terms of both lag-free response, outright performance and sound -- for the finest turbo V8s from BMW and Audi.

The difference is Mercedes is the only car-maker still game enough to deploy one in a sedan this size, which not only gives C 63 owners bragging rights, but makes it as quick as it is efficient, with claimed average fuel consumption of 8.6L/100km -- 30 per cent less than the old C 63.

It's also more frugal than the GT S, but again there's not much in it. As you'd expect, the biggest difference between these similarly-powered AMGs is dynamics, but the contest isn't as lop-sided as you might expect, even in the daunting, concrete-lined corners of Australia's most challenging public road circuit.

Yes, the GT S felt more planted at speed, thanks to a totally different aluminium spaceframe chassis that has a broader footprint, lower centre of gravity and mounts its engine behind the front axle and its transmission ahead of the rear axle, producing the same 47/53 front/rear weight distribution as the SLS.

The C 63, on the other hand, rides on the steel monocoque architecture of the W205 C-Class and e-up, but much of the front and rear suspension is developed by AMG, the track is widened and the suspension is firmer, lower and features AMG Ride Control adjustable damping, like the GT.

Also like the GT S, the C 63 S has a new electronically-controlled clutch-operated limited-slip diff, which unlike the non-S C 63's mechanical LSD opens and closes continuously in the search of traction both under brakes and power, gives it a surprising level of cornering traction -- especially while trail-braking deep into bends.

The 'S' powertrain and chassis upgrade also includes active engine mounts that -- as on the GT S and selected 911s -- aid both ride and handling, plus a performance exhaust, 19-inch AMG wheels with 245/35 front and 265/35 rear tyres, adjustable steering and transmission modes as part of AMG Dynamic Select.

All this is wrapped in revised front and rear sheetmetal to accommodate the V8 and broader footprint, including pumped out guards, a domed bonnet and a front-end that's extended more than 50mm. Even so, with expensive exterior options, it's all perhaps a little understated.

Perhaps the biggest difference between the C 63 and GT from behind the wheel is the steering. While the sedan runs an electro-mechanical set-up, I actually preferred it to the coupe's variable-ratio hydraulic system, which for me felt too light at all speeds and in all drive modes (Comfort, Sport, Sport+ and Race).

Although both cars readily pushed their noses in tight downhill corners like The Dipper and Forrest's Elbow, the C 63's extra meat made it feel less prone to understeer and instilled more confidence to get back on the gas earlier.

The GT's lower, wider and better balanced body certainly rolls and pitches less than the C-class and it probably carries more speed in any given corner, but the sedan's less agile but better weighted steering felt like a better match for the acres of grunt under both bonnets.

The C 63 might lack the stability and agility of the GT, but it's certainly less intimidating at the limit and easier to drive on the throttle, allowing many drivers to access far more of its considerable dynamic talent.

In Race mode particularly -- when the steering, suspension, transmission and stability control settings permit maximum fun – we can't think of another luxury sedan that communicates its intentions so intimately or makes average drivers look so good.

As far as we could tell on Mount Panorama's smooth but grippy new surface, the C 63's ride was also more comfortable in any given damping mode, but that's not saying much because it's still pretty firm and could get tiresome on rough country or suburban roads.

And in Sport mode or with the 'loud' exhaust mode selected, the booming in the back seat is almost unbearable. Is this really a Mercedes-Benz, I asked myself at one point during a taxi ride.

In quiet, comfort mode, however, the C 63 presents all of the sophisticated refinement, exquisite design and material quality of the award-winning C-Class, and its extensive standard safety and equipment list that's too extensive to regurgitate here.

Suffice to say the C 63 comes with all the current C-Class goodies like the latest COMAND multimedia system with 213mm colour display and, from the C 250 up, active cruise control, blind-spot and lane-keeping assistance.

It then adds AMG attractions like a flat-bottom steering wheel with aluminium shift paddles, AMG-specific instrument cluster with lap timer and turbo boost gauge, the choice of three Nappa leather colours, metallic paint, panoramic sunroof, LED headlights with adaptive high-beam, head-up display.

To this the S adds items like a 360-degree camera, digital TV tuner, Burmester 590-Watt 13-speaker surround sound and heated memory front seats, plus options including interior trims, wheels, ceramic brakes, exterior carbon-fibre package and the Edition 1 cosmetic pack.

Performance and efficiency aside, all of this safety, convenience, luxury and choice makes it easy to justify a pricetag that's double that of an equally quick but even bigger homegrown V8 sedan from HSV.

But when it's almost as quick and just as engaging as the GT supercar – and can carry more than double the number of people and their luggage for half the money -- it's plain to see why the new C 63 will write a blockbusting new chapter in the success story of AMG.

2015 Mercedes-AMG C 63 S AMG pricing and specifications:
Price: $154,510 (plus on-road costs)
Engine: 4.0-litre twin-turbo V8
Output: 375kW/700Nm
Transmission: Seven-speed automatic
Fuel: 8.6L/100km (ADR Combined)
CO2: 200g/km (ADR Combined)
Safety rating: Five-star (ANCAP)

What we liked:
>> Epic engine
>> Involving dynamics
>> Refinement and equipment

Not so much:
>> Understated styling
>> Questionable ride quality
>> Back-seat noise in sport mode

Also consider:
>> Audi RS 4 Avant ($151,400 ORCs)
>> BMW M3 sedan ($156,430 plus ORCs)

Related reading:

>> Mercedes-AMG GT S 2015 Review
>>

>> AMG GT sold out until 2017
>> Mercedes-Benz GLC to tackle Audi Q5 from December