Mercedes S63 AMG vs classic 450SEL

Mercedes-Benz S-Class is, by tradition, the kind of car that wears its pearls of technological innovation and luxurious appointment beneath a handsome-but-bland shell of Mercedes-range hegemony. There are more arresting Benzes. Sportier, swoopier, grand-entrance Mercs. But the S-Class has always been the one that slides by, delivering on-board satisfaction before kerbside appeal.

The car that glories in a certain lack of attention, but never lacks for interior appointment. If you think about it, an S-Class has always been the equivalent of wearing a fur coat inside out.

The new S63 AMG continues that tradition, and then some. Because, for the moment, this is the quickest, most luxurious, newest S-Class you can buy, making it - supposedly - the apex predator in the fast and fabulous limousine market. And although the S63 might be slightly less discreet than one of its smaller-wheeled diesel brethren, it still doesn't loudhail its potential. Yes, there's largesse to its street presence (all the S63s we'll get in the UK are LWB), but unless you were in the know, you might miss the bi-turbo V8 badges on the wings and have no idea this monster limo could comfortably outpace all but the most modern Ferraris.

You did read that right, by the way. The S63 is capable of 0-62mph in a scant 4.4secs, and - with the appropriate limiter-extend option ticked - some 186mph. We won't be getting the four-wheel-drive variant in the UK (0-62mph in a much more acceptable four seconds), Merc quoting the cost-versus-sales benefit of redesigning the AWD system to convert to right-hand drive or some such paltry excuse, but it's probably enough for most.

Still. The S63 looks... meaningful. But not exactly pitbull aggressive. Certainly not the festival of chintz you might expect given the specification, which would shame a Russian oligarch. Because this thing - as standard, I hasten to add - is brimming with the kind of cutting-edge tech and pointless brilliance that would make most of California's high-end consumer geeks explode in a hipsterish, glitter-filled, early-adoptergasm. Usual for the S-Class, but worth mentioning all the same.

But, to misquote Buddha: "You can only really know where you are when you've worked out where you've been." Which is why there's a W116 Mercedes-Benz here, too. The first car officially called the Sonderklasse, or ‘special class', when it was released in 1972. And, happily, this example is the 450SEL 6.9. The quickest, most luxurious, most technologically advanced S that Seventies money could buy. The S63 AMG before the S63 AMG even existed - the car chosen by Sophia Loren (who had hers converted to an estate to transport her dogs), Frank Sinatra and James Hunt for when they weren't being impossibly glamorous, to name but three. The vehicle chosen as the camera car in C'était un rendez-vous. The coolest S ever. So does the original imperious, fast S-Class take pride in its offspring, or has the family tree gone a bit... nouveau?

Comparisons seem a little fey at first. Mainly because the 450SEL is simply a gorgeous, clean-looking car, while the modern S63 looks a bit bloated by comparison. We'll forgive that, modern ideas of safety having legislated the absolute elegance out of lots of modern metal, and look instead at the confidence of the 6.9. The subtlety. The only difference between this and the smaller-engined V8 was the boot badge and slightly wider tyres, but under the bonnet is a 6.8-litre (yep, Merc was a bit free 'n' easy with rounding-up even then) V8 that puts out a reasonable 286bhp, and an astonishing 405lb ft. That amount of torque means it uses just three forward gears, and puts on speed like a hot hatch: 0-62mph in 7.5 and 140mph is respectable now; in 1979, it must have seemed ridiculous.

It has disc brakes all round, ABS, thermostatically controlled heating, aircon, central locking and a headlamp wash-wipe system. Airbags were even an option on some later versions. Sounds simplistic now, but when you remember coq au vin was considered cutting-edge gastronomy when this car was released, it really has a veritable feast of tech. In context, the 6.9 was the saloon equivalent of... well, of the S63 we have here.

The equipment list for the new S is literally too comprehensive to go into here, but even the highlights are numerous and startling, the best of what automotive has to offer. All the lights, including head and tail, are adaptive and super-bright, low-draw LED. The gearbox, exhaust, brake lights, bonnet, safety systems, stereo, braking system, cruise control, seats and myriad other functions are all adaptive or active, meaning the S63 probably thinks more than you do. Certainly more quickly. It has night vision, a rear seat that converts into a reasonable facsimile of an executive jet's bed, more music storage than the average home computer, three televisions, a 360° camera, a fridge, on-board internet and something called an Air Balance Package for "ionisation, filtration and scenting", with various smells available to suit your mood. It also has stretchy nets in the boot.

Which you will need. And that's just a small selection picked randomly from a spec sheet that unrolled onto the floor like a wayward till receipt roll. The tech-shock continues when you get into it, because the S63 feels like a spaceship. A tight, warm, clean pod of absolute isolation, black leather and metallised ash wood, a fortress of solitude from which to attack the vagaries of travel. The complete antithesis of the 6.9, which is a joyous festival of beige velour.

It's almost literally like night and day: the 6.9 is bright, light and simple, with dials that simply include water temperature, oil pressure and fuel level, a speedo, a rev-counter and a clock. The heater-controls range from hot to cold via a lever, with a rotary control for the fan speed. You adjust the seats by more levers - and there is simple joy in that. The S63 has two massive TFT screens in front, displaying a bewildering amount of information. The seats are infinitely adjustable, the huge central tunnel randomly decorated with cubbies and slots filled with technology nicked from the set of Starship Troopers.

But despite all the postgraduate-level technology - seriously, you'd be discovering new things about this S63 four years after you bought it, even if you dedicated a fortnight to actually reading the manual - the S63 drives like nothing else. Mercedes Magic Body Control is aptly named. It feels like witchcraft. Pick a gear (pretty much any one of the seven available will do, thanks to 664lb ft of torque) and drive around a corner. Cameras will look at the state of the road ahead, and tell the suspension what to do to soothe away the bumps. Of course, this has benefits for straight motorway ride, but the way the suspension breathes as you mount a spirited attack on a pimpled B-road makes for a car that feels like a massive, part-anaesthetised Lotus Evora. That might sound stupid, but it's true. And the grunt is simply huge. Not visceral like other AMG product - indeed the AMG badge is slightly disingenuous-feeling here - but thumping. It belts away from other traffic like it's just ingested a lungful of nitrous and brimstone.

Of course, the 6.9 has its own version of Magic Body Control in the form of full hydropneumatic suspension, a system invented by Citroen then made better by Mercedes. Another innovation of its day, and one that lends the 6.9 a better straight-line ride than three-quarters of the cars on sale in 2013. But tip the ancient and original S into a bend and it still requires settling and a decent amount of head-lean, even though the standard limited-slip differential will allow it to maintain an utterly surprising tightness of line - even on 14-inch wheels with 70-profile tyres that look like circular bouncy castles next to the painted-on 20-inch rubber attached to the S63. It's brilliantly amusing, but when you get into the new S, you realise just how far cars have come, and how good they really are today. Less mechanical, yes. Less connected, yes. But empirically better in almost ever other aspect.

But you know what? Despite the absolute differences created by 40 years of progress, the 450SEL 6.9 and the S63 definitely feel like cars from the same mould. A comfortingly distinct lineage between what was the best large luxury car in the Seventies, and the most astonishing fast limousine of 2013. They have a distinct character, one that takes slightly longer than usual to properly discover. But there's something more than that here, too. Something that sets the S-Class apart.

It's about confidence. It's about money versus power. The thing is, money likes to be noticed. Money travels in a supercar, a yellow Bentley or an enormous SUV filled with non-specific ‘entourage'. Even when money thinks it is being subtle, it shouts in a stage whisper, unable to contain itself. Power, on the other hand, well, real power invariably travels in a fast Mercedes S-Class. And, given the choice, I know which one I'd rather hitch a lift in. Because power speaks softly. But always, always, carries the biggest stick.

Pictures: Rowan Horncastle

This feature first appeared in Top Gear magazine