Porsche 911 Carrera vs Mercedes-AMG C63 S Coupe

Something is indeed working its way up the mountain. Germany’s Lowenstein ranges hunker in the morning stillness, not unlike ourselves as we sit on a road that ends at a construction site. Company is unlikely. But we are expecting.

Down in the valley a murmur turns to a dim growl, which grows into a bark that’s discernible – if you know your cars, that is.

Two cars; one is clearly a V8 and the other an old friend. Porsche’s 911 is more than 50 years old now, but the entire time it has made more or less the same racket – one a trained ear can spot swirling up a German valley. Yet while the sound is familiar, it’s different just the same. Like a kid whose voice you’ve known, but then he turns 13 and it drops an octave.

Plonk both these two-door missiles on a drag strip and it’ll be a dead heat to 100km/h, both claiming 3.9sec sprints.

But that’s pretty much where the similarities end. The engines sit at opposite ends of the car, and themselves count different cylinders and displacement. One’s attached to a super-responsive twin-clutch, the other a lazier, more conventional auto. Then there’s the fact one was created as a sportscar from the word go, while the other is, at the end of the day, a variation of what is the most popular taxi in Germany.

It’s at the Mercedes dealer that the envy and admiration comes a lot cheaper. The C63 S Coupe will cost about $160,000 (price hasn’t been confirmed yet) to the 911 Carrera S PDK’s $258,750.

A higher top speed aside (309km/h versus 290km/h), the extra dough means you will be supporting less of the Middle East economy in the 911, its 7.7L/100km better than the Merc’s 8.9L. But you’ll have to screw a block of wood to the throttle pedal’s backside if you want to get anywhere near those claims.

It is the Porsche’s engine that has undergone the greatest personality change. While the C63’s new 4.0-litre twin-turbo V8 still cranks out the torque – and a satisfying V8 soundtrack – the mildly turbocharged Porsche has evolved from something a little hoarse and hungry for revs to an engine with manners and plenty of flexibility.

Power is up 15kW to 309kW, but where the torque curve of a Carrera S used to ramp up with all the aggressiveness of a beginner’s ski slope, these days it’s more Himalayan, a plateau of 500Nm – an increase of 60Nm – is all yours from 1700rpm to 5000rpm.

It’s when the road starts to bend that the C63 is the more entertaining, and frustrating, drive. Laying down all that muscle can be a challenge for the driver as much as the rear tyres, and with the ESP on, you could have as much fun in a C450. But ESP in Handling mode changes the C63 from a punk in hoodie and trackie-dacks to getting out the boxing gloves. And ESP Off, well, if you’re not wide awake you quickly will be.

On paper the Porsche looks hampered by a potentially even-more-ill-fated dynamic weight distribution, yet it hangs on with more skill and corners with greater determination. The bad news is it needs a bigger stage to excel; it’ll cheerfully switch from understeer to oversteer if you clobber the throttle, but the process takes a little longer than the AMG and demands a heavier right foot.

Both cars could sound better, too. Once upon a time car companies couldn’t fit mufflers big enough to these kinds of cars, but now it’s the other way around. In this company there’s no shortage of fake throttle blipping, computer-controlled upshift blats and artificial lift-off fireworks, yet given customers are going for optional sports exhausts, it seems it’s what the masses want.

These days, too, many sportscars try to make everyone happy, being able to tootle to the shops one second and then devour a set of tyres on a track the next. This manifests itself in buttons, and the Porsche is the latest to join the party with its manettino-like steering wheel rotary knob. In Sport Plus it behaves like it’s trying to win a spot on A Current Affair. In Normal and Drive, the excitement levels become limp, the transmission grabs the tallest gear as quickly as possible, and the initial throttle response becomes almost dopey.

In their Manual modes, the PDK looks to win out on paper for performance, with its unbelievably quick and crisp shifts up and down. But it’s closer in the real world. The Merc’s Speedshift torque-converted tranny is marginally less efficient but slightly more emotional, able to slam up the gears with impressive rapidity, yet in cruise mode swaps cogs in a manner more relaxed than the Porsche.

On paper, too, the AMG GT might look the more suitable car for comparison with Porsche’s new force-fed Carrera. But, the C63 is the more sorted, sharper and more chuckable back-road missile than its attention-grabbing big brother. It’s the more sensible buy, too.

Everything else AMG has made to look meaner; all the flicks, splitters and diffusers will have boy racers in Nissan Silvias trying to race you at the lights. The changes run more than skin deep, too, with AMG thoroughly reworking the suspension, quickening the steering and, of course, installing an engine more than fit for autobahn blasting.

Much like the 911 GTS, the new Carrera S impresses with its polish. But it’s a different car now, no less capable yet more relaxed, progressive and fluent. It’s incredibly well tied down, yet expressive, precise and sublimely balanced, and it includes you in the process of cornering in a way many other so-called sportscars could only dream. Turn-in ability can be truly arresting, stability beyond 200km/h now no longer likely to bring on cardiac arrest, and the extra-cost carbon-ceramic brakes are breathlessly good.

It’s time to wrap up the day, but there’s time for thought as the cars tick themselves cool. The C63’s personality is split in that it’s equally talented a stealth cruiser as attention-grabber in front of the right crowd. Despite its boisterous character and hot-rod soundtrack, it’ll bomb up a road with impressive talent and will be occasionally tricky to tame but always rewarding.

It has got its act together over bumps to the point it’s more confidence-inspiring than the Porsche. Then there’s the practicality element the 911 can’t match, with semi-useable rear seats and a decent boot. The C63 epitomises all the attractions (and flaws) of a rear-drive muscle coupe.

Both the 911 and C63 go like stink, thanks in no small part to some induction assistance, but that’s about all they have in common. The new turbo Carrera S is the most sensible and accessible 911 we’ve driven for a long time, and the two-door C63 the most focused C-Class yet. If price and emotion top your list of criteria, go the blue car. If it’s prestige, panache and perfection, go yellow.