With this Ring ...

Beneath the shadow of the Eifel Mountains in Germany, about 70km south of Cologne, lies the toughest, most dangerous and demanding purpose-built racetrack in the world.

The infamous N&#252rburgring stands as the ultimate arbiter of speed and chassis ability among the world's car manufacturers. Road cars are brought here to its 20.81km and 73 turns filled with blind crests, 300km/h-plus straights and rutted and off-camber surfaces. Road cars like our four assembled combatants have been honed by the Green Hell and wear 'tuned at the N&#252r' as a badge of honour.

But how effectively does development at this remarkable track translate into road-going talent? We first went trackside to watch the race-bred versions of this foursome do battle in the N&#252rburgring 24 Hours, then ventured out to the dipping, bucking roads that surround the infamous 'Ring to hammer their street-legal brethren.

First up, and indicative of the breed, is the Aston Martin V12 Vantage. By shoehorning the DBS coupe's 12 cylinders under the vented Vantage bonnet, the engineers at Gaydon have created an awesome machine. When you first lay eyes on the V12 Vantage, it seems absurd that a body this small should be packing nearly 6.0-litres and 380kW. And closer inspection of the tyre tread pattern and the aerodynamic tweaks pinched straight from the N24 race program shows that this Brit wasn't just designed as some straight-line monster, either. While Aston may not carry the same racing pedigree as Porsche, the V12 Vantage is a big single-digit salute to the supercar establishment, raising expectations of this little coupe with the mighty V12.

Next, a car that makes the Aston seem soft and under-engined - the Corvette ZR1. The crowning glory of American excess, this supercharged, 6.2-litre small-block V8 beast belts out 476kW, but it's the torque that's really astonishing - 819Nm, and all of it available at just 3800rpm. Fortunately, as with the Aston, the wheels (19in at the front, 20s at the rear) hide huge carbon-ceramic disc brakes. So, piling on speed then wiping it off again won't be a problem. But how will the Magnum-totin' American handle? Its carbonfibre roof, bonnet, splitter and front bumper have helped keep weight down to 1528kg, and if this king 'Vette's chassis builds on the solid foundations of the impressive Z06, we're in for a treat.

Germany's first entrant is Audi's R8 V10. In plain old V8 form, it's been an all-conquering hero and widely regarded as the best car to ever roll out of Ingolstadt. Conventional wisdom, then, would suggest that with the addition of two extra cylinders and another 77kW (bringing the total to 386), this R8 ought to turn every road it travels into pure gold. The chassis has also received some minor adjustments, mainly to cope with the added weight and grunt of the V10, but also to impart a new degree of sharpness and purpose. Thankfully, we were able to avoid the R-tronic semi-automatic transmission in favour of the wonderful, open-gated manual gearbox, and if the notoriously fickle Eifel Mountains weather decides to dump rain, then the all-paw quattro drivetrain may simply walk away from the others.

Finally, we come to the bargain end of the line-up with the $280K Porsche 911 GT3. We already know that this car is nothing short of exceptional, and no test of road racers would be complete without it. But with only six cylinders, 60kW less than the next least powerful car here and offering barely half the torque of the ZR1, will the GT3 simply be out-gunned? Obviously, the lowest kerb weight here (1395kg) - and the fact those boffins at Porsche tend to do a pretty good job of little things like steering feel and chassis balance - will work in the GT3's favour, but for once I get the feeling the 911 isn't going to have it all its own way...

Brought together for the first time in a sandy carpark a few clicks from the 'Ring, these four machines play out an automotive wet dream. Fantastically diverse and stunningly executed, they are the pinnacle of their respective manufacturers' pursuit of speed. Engines from six, through eight and 10, to 12 cylinders; situated in the front, middle and rear of the chassis; rear- and all-wheel drive. Does it get any better than this?

Our consensus is that the wedgy, pertly-proportioned Vantage is the visual standout, even in white - a colour that somehow makes it feel like it should belong to the hot wife of an ageing millionaire in Monaco. Then there's the Audi R8, all swooping lines and still so futuristic three years after launch, and very Will Smith in its box-fresh-sneaker white. The GT3 looks retro and almost ungainly in this company, but also small, lean, focused. If it were in white, too, it would have been the easiest to sneak unnoticed onto the 24 Hours' rolling start. The ZR1 is mean, angular and tarmac-scraping low, but whereas we're all delighted in having cars like the Audi show off their mid-mounted engines through transparent portals, the Corvette's little window onto its blown 6.2-litre LS9 V8 isn't quite so successful.

I claim the Audi's keys first as we head for a nearby ribbon of road where we're going to base ourselves. You feel almost single-seater low in the R8, bum skimming the tarmac, and although the switchgear is no more upmarket than that in a TT, details like the carbonfibre hoop that arcs from the transmission tunnel around the back of the instrument binnacle and into the doors make the R8 a special place to be. The throttle is scintillatingly sharp, revving the V10 behind you like it's hardwired into your frontal lobe; the damping is delightfully precise and you pour the car through corners. Yet all the major controls work so effortlessly that you could use this every day.

Then you experience the almighty pace of which the V10 is capable. There's masses of urge from 3000rpm and the noise and speed generated early is deceptive. You initially find yourself palming the knurled gearknob early and short-shifting - clack-clack - through the open gate at about 6000rpm. Yet peer through the steering wheel and concentrate on the tacho framed in front of you and you'll see that you've halted the needle in the midst of a furious scramble that stretches all the way to 8500rpm. High up there, it sounds, feels and punches a lot like the Lamborghini Gallardo V10 to which it's intimately related. But in true Germanic fashion, and perhaps to preserve the aura of the Raging Bull, the engine has been de-tuned slightly and the volume has been turned down to seven - it's more like a potent martini rather than slammed vodka shots.

Of course, if you want the whole damn distillery then you need the car that's shrieking and roaring up ahead of me every time the driver stands on the throttle...

Yes, it's the Corvette. But do you really want a ZR1? You know those tests where the writer says that they knew just by the smell of the key fob as they walked towards the car that it was a winner? Well, I'm afraid the ZR1 is the car that, within the first few kilometres, everyone knew was going to finish last. Even just pulling out of a rest stop, each of the far-flung corners of the 'Vette seems to have its own subtle agenda. The Magnetic Selective Ride Control dampers (the same Delphi-developed technology HSV employs) are not, unfortunately, an improvement over the Z06 Corvette's conventional hydraulic set-up. Just as with the Audi's adaptive dampers (also Delphi units), a switch flicks between Touring and Sport modes and alters the damper response appropriately.

But unlike the Audi, the ZR1's switch has to be left in Sport mode just so that the suspension feels like it has some control over the vertical movement of the wheels. It doesn't actually feel as though it's sharpened anything, it just reduces travel. In fact, on Belgian motorways, one tester claimed the ZR1 was almost unbearable, such was the tyre noise and wheel-slap.

But then you press the 'very loud' pedal and are savagely reminded of what Corvettes do best. Ideally you'll want to be in a gear lower than you're used to, or think you'll require, because second is good for 155km/h and third for around 210, but with that tsunami of torque underfoot it doesn't really matter what gear you're in.

The process goes something like this: plant the right foot, and the big leather bucket seat you're strapped into rocks back unnervingly as the forces of physics are unleashed, then you're gathered up and hurled towards the horizon. And as speed builds, so the car appears to grow around you like some bad Alice in Wonderland trip; its extremities becoming more and more remote and even the steering wheel seems to stretch farther away. Then, just when it feels like the Corvette simply won't fit on the road any more, you have to change gear (thankfully via an improved, short-throw six-speed 'box), but soon the ZR1 is growling again, so you lift off - except engine response is lazy and acceleration continues for a split second while you transfer your foot from accelerator to brake. Which, with the sheer pace the ZR1 is capable of, is about as reassuring as a politician's election promise...

At least the massive carbon disc brakes are exceptionally powerful and offer a decent amount of feedback, but the feedback you get through the steering is the automotive equivalent of an epileptic fit. With 285mm Michelins at the front and gargantuan 335mm rubber at the rear, the American dream tugs, weaves and tramlines all at once. Truck-rutted inside lanes of motorways are best avoided, so what it must have been like to wrestle this car to its 7min 27sec lap of the N&#252rburgring is almost unthinkable...

The morning passes and we move on to cornering shots. And quattro all-wheel drive or not, the R8 is very, very rear-wheel drive if you want it to be. When the momentum of that mid-mounted engine pendulums on lift-off, you had better be ready with a cool head and armfuls of opposite lock.

Later, we lunch on burgers and chips from the cabin next to the Döttinger-Höhe petrol station and swap opinions. We all agree that the Porsche's gearshift can be a little baulky and that the Aston is hugely impressive. "It's only when you check the speedo that you realise how bloody fast you're going, which is the ultimate compliment, really," one tester said. Another reckoned the ZR1 "makes everything else feel slow, but is so crude".

"Bonkers," was the most succinct summary of the Corvette.

Our debate is just heating up and chips threaten to fly as we get a call saying that we're allowed on the Nordschleife to do some photography. We're not permitted to do laps, which is frustrating (I decide to stay behind for the public session the following evening, which will turn out to be terrifyingly wet),

but it is wonderful to be able to drive the 'Ring in something other than a sweat-soaked state of nervous tension and it's a curious thrill to sit on the bumpy, hallowed surface
of the Karussell, taking it all in with only the sound of a camera shutter clicking away.

After a while, though, just as we think we've deciphered some particularly juicy graffiti on the track, someone feels a drop of rain, someone else spots lightning in the distance and a third person thinks they can hear thunder. It's definitely beer weather closing in, so we head for our hotel. But by the time we've driven the 32 kays, the weather has blown over and it's nice enough to sit outside and enjoy our Bitburgers. But I've got plans before the beer...

Having driven it recently, I know just how good the Porsche is. I was lucky enough to get behind the wheel of the Aston recently as well, so I know how impressive that is, too. Both are five-star cars. Both are challenging for top spot along with the Audi. I won't be happy going to sleep tonight without a proper back-to-back drive between the V12 and the GT3. What else is a bloke supposed to do?

I coerce another tester into accompanying me, so he jumps into the Porsche and I swing the Aston's door up and drop into the best driving position on this test. With the wheel low and close to your chest and the slightly reclined seat offering an almost perfect blend of luxury and grip, it feels right straight away. If AM could just position the gearlever a few inches farther forward, there would be nothing to complain about.

Press the (cough) Emotion Control Unit - better known as the key - into the centre console and the starter spins for a moment before the Aston's V12 bursts into life, rocking the nose slightly as it fires up. The gearshift encapsulates the feeling of the car as a whole, despite that brutally rapid engine. The road opens up straight and true right outside the hotel and a quick prod of the Sport button releases the full, guttural vocal range of engine and exhaust as we tear away. In some ways the Aston and Corvette are the most comparable cars here - oversize engines up front driving the rear wheels - but the Aston feels slightly short-geared where the Corvette is long. And where the Vantage is compact and confidence inspiring; the ZR1 feels big and intimidating.

I turn off the main road with the 911's xenon and LED lights bright in the mirrors, catch the Aston's tail as the Pirelli P Zero Corsas spin up on a rain-soaked patch of tarmac, hold the slide just for fun and then grab third and fourth before sinking the middle pedal towards the carpet as a long right-hander approaches. The brakes feel strong all the way through the travel and there's weight in the steering around the straight-ahead. The nose grips initially as you turn in before the wheel goes slightly light in your hands as the weight of the big engine up front encourages the car to waver fractionally from your intended line.

This is the understeer that most people comment on after an initial drive in the V12 Vantage, but on second acquaintance you find that it's not scary, wash-out understeer; it's telltale and workable, an invitation to play with the balance of the short wheelbase and use the throttle and steering to adjust grip throughout the corner. Then the road unfurls in front of you and no matter what gear you're in or what revs you're at, as soon as you get on the throttle you feel tapped into the juiciest part of the torque curve and face-peeling acceleration is unleashed. It's involving, exciting, beautiful and balanced. But is it better than a 911 GT3?

We swing into a side road and turn around before leaping out and swapping places, barely acknowledging each other as we pass between the still-running cars. I slot down into the GT3's optional buckets, which grip you so intimately at the thighs, hips, ribcage and shoulders that you should be demanding dinner and a movie first. If you want to retain a little more of the 'road' half of the road-racer equation then perhaps opt for the thickly padded standard seats rather than these Carrera GT-sourced fixed buckets, but right now I want these.

As we pull out in tandem and track back to the hotel, I lower the sun visor as the evening sunlight skims over the fields. The engine hits its stride as the revs surge beyond 4000rpm and the hairs on the back of my neck prickle in appreciation as the flat six begins to howl. Even after jumping out of a car as charismatic as the Aston or as beautifully resolved and of such ingrained quality as the Audi, the GT3 feels on another level entirely.

The following morning I nab the key to the GT3 again and go for another drive to try and pinpoint exactly what it is that sets it apart. It comes down to this: it feels more honed than any other car here. Yes, even among this elevated company. There just isn't one iota of slack in it, so you are never, ever guessing or making allowances for the car. You can literally drive as hard as you want, and the harder you push, the more rewarding it is. More throttle, less lock, fourth gear - it all happens so incredibly naturally. You can brake so fiercely that it feels like impacting a brick wall, or throw the nose into a fast corner so hard that you wince and hold your breath, and yet you'll always find the car taut underneath you, telling you calmly and with clarity everything about the forces working on the tyres, chassis and drivetrain. And because it never dithers, you gain confidence and find yourself being the best that you can be, and that is every bit as intoxicating as the huge grip the GT3 generates.

So, to the finishing order starting with the Corvette ZR1. "There is a pleasing lack of bullshit about it, but a very un-pleasing lack of talent, too," was one tester's initial assessment. After driving it in the wet (with traction and stability on), he was less polite. The Corvette crashed out in the 'Ring 24 Hours and, metaphorically, it crashed and burned in this test, too. You can't help but love that engine and if you think that driving fast should feel like constantly fighting off an accident, then you might love the ZR1. But if you want a good Corvette, buy the 7.0-litre Z06 and save yourself enough money to buy a Boxster too.

If you want an Audi R8, you can save yourself money there, too, by buying the V8 model that looks almost identical to the V10. But unlike the Corvette, this isn't because the V10 is a flawed car - far from it. But where the standard R8 has a delicacy to it, it seems the V10 sits a bit more heavily on the road and is therefore slightly less magical. Of course, the upside of the V10 is that fantastic engine, but it would have been nice if Audi hadn't relied entirely on an extra 75kW and a new soundtrack to differentiate it.

However, where Audi and Chevrolet have disappointed in their attempts to improve on their lesser-engined models (albeit with varying degrees of success), in its monster-engined Vantage Aston has struck gold. In a way the V12 is the car we always hoped the V8 would be, offering a decent ride, proper supercar performance and engaging handling. Add this to the Aston's achingly beautiful looks and it's simply a fantastic car. "This is clearly the best Aston the company has ever made for people like us," reckoned one pilot. "Money no object, I'd have it over the Porsche. Well, maybe."

Maybe. Arguments were put forward that the GT3 is now too fast, too grippy and too brutal. One suggestion was that Porsche should have given it the same power as the previous-gen model but reduced the weight. We all nodded. But every time anyone returned from a drive in the GT3 they'd emerge from the car smiling and shaking their head. You simply can't deny this 911 its victory. It is wonderful. If you want the ultimate road racer, the car that will turn any road into your own personal Targa Tasmania and make you long for your next stint behind the wheel, then you need a GT3.