The epitome of our enthusiasm and fascination for sustaining big speeds over big mileages, they embody a blend of prestige, presence and performance that place them in motoring's major league. That they stop short of the exhibitionism and impracticality of a stratospherically priced supercar just seems to add extra strings to their bows.

Not that you should feel short-changed if your dreams 'only' stretch this far. The consummate Porsche 911 C4S, seductive Maserati 4200GT and newly revised Jaguar XKR are three of the finest modern exponents of the classic GT genre. To hold the keys to any one of these cars in your hand is to truly appreciate the meaning of the word wanderlust. Which is why rather than idly trotting out that empty clich΃© about one-hit forays to the Mediterranean, we are going to put mileage where our mouth is. Driving the length of France non-stop, we'll test their mile-munching capacity with a 700-mile autoroute schlep. Then, in a total change of pace, we'll plot a course for one of the greatest and most historic hillclimbs in the world - the daunting, spectacular Mont Ventoux - to see how each cuts it as an out-and-out driver's car.

It's an intriguing, double-edged test of three very different cars. The all-wheel-drive, manual 911 is clear favourite to revel in the twists and turns of Ventoux's barren, volcanic slopes, but its focus on engrossing dynamics could prove wearing on the arrow-straight peage. The supercharged Jaguar's effortless pace and cosseting delivery is tailor-made for the autoroute but its bulk and supple set-up is likely to be rather less suitable for scratching to the 2000 metre summit of Ventoux. Dark horse here is the Maserati. We'd hoped to have a manual version, but in many respects this paddle-shift Cambiocorsa version should strike the ideal balance, combining easy motorway flexibility with brutal, normally-aspirated response and lightning-fast gearshifts on the maximum attack mountain ascent. Which car wears the yellow jersey for the return leg home is, frankly, anyone's guess.

That old GT romance is in short supply at the Meaden household at 2:30am on a Monday morning, when the strident tones of a Radio 4 newsreader blare insistently from the bedside alarm. In almost a decade of working with photographer Gus Gregory, this is the most extreme example of 'Gus O'Clock' I have ever experienced. It's so early it hurts. But a 3am departure is what's required to get me from my sleepy Northamptonshire village to the Nikon-wielding nightwalker's Reigate lair, and then on to Folkstone for a 6.30am Eurotunnel train.

Despite the sleep deprivation I'm actually relishing the prospect of taking a large bite out of Europe in Jaguar's finest. Yesterday, Eddie Irvine raced to a fine third place at Monza, and although I've long been wondering why Ford persists in bankrolling Jaguar's disastrous, politics-riven F1 effort, the sight of a British driver, clad in British Racing Green up there with Ferrari is a genuinely stirring sight. As that surge of pride is still with me in the early hours of Monday morning, perhaps there's more to this F1 halo effect than marketing babble.

The XKR has long been a supremely effective, desirable machine, but thanks to the S-Type R, the XKR now benefits from the new saloon's larger, 4.2-litre, supercharged V8, along with a host of other detail changes, both to the hardware and cosmetics. Headline news is the power and torque increase, up from 370bhp and 387lb ft to 400bhp and 408lb ft, but there have also been tweaks to the CATS suspension and the steering assistance, and the fitment of some mighty Brembo discs and callipers. This car has all the 'R Performance' goodies, including stiffer springs, those incredible 20in 'Detroit' alloys and more supportive sports seats.

Visually the XKR has never looked better. It really is a terrifically sexy shape, all teardrop curves, muscular haunches and sleek aggression. Someone at Jaguar must be a mind reader, for those wheels, the Jaguar Racing Green paintwork, crimson leather, silver-grey wood and tactile all-leather 'R' steering wheel is my ideal combination. Don't wrap it, I'll drive it home!

Despite the obvious physical allure, driving an XKR never gives me an instant hit of excitement. Perhaps it's the auto 'box. More likely it's the nagging feeling that Jags are driven by people a generation older than me. Whatever, I'm an hour down the motorway before it dawns on me that I'm actually really enjoying the Jag, luxuriating in the instant, effortless response, glassy gearshifts and deliciously soothing ambience. It is utterly sublime.

A few hours later, and with Gus and his camera gear stowed, the Jag's xenon headlights cast a cold, sharp beam of light across the unmistakable rumps of a yellow C4S and dark green Maserati waiting at the Eurotunnel ticket barriers. The contrast between the two is stark; the chic, aloofly aristocratic Italian and the brash, muscle-bound nightclub bouncer from Stuttgart. Where the slinky Jag fits in, only time will tell.

After 40 minutes of immersion in the muggy, stale fug of the Eurotunnel carriage it's a pleasure to emerge into fresh air and lightly trafficked roads. The sense of freedom you get on French autoroutes is incredible. No hassle, no jams, no selfish trucks blocking the middle lane, just fast, free-flowing, well-disciplined drivers making rapid progress. The temptation to exploit the lack of traffic is huge, but past experience suggests Gendarmes are getting increasingly tetchy about Brits using their motorways as race tracks. Reluctantly we settle into a discreet 100mph cruise and watch with dismay as turbodiesel after turbodiesel leaves us in a turbulent wake of soot and carcinogens.

Pretty soon we make the first of many fuel stops. Predictably the smaller, lighter Porsche is the most frugal, managing a comfortable mid-20s average, although its small fuel tank means no great range advantage. The Jag and Maser are thirstier machines, managing similar and similarly depressing 20mpg averages. Only the Maser's bigger tank gives it the legs on the XKR.

Swapping from the Jaguar into the Maserati shouldn't be much of a culture shock. Both have big capacity V8s, two pedals and a bias towards luxury. In fact with four full-size seats, compared with the Jag's laughable rear and the 911's no rear seats whatsoever, the 4200GT takes its GT role most seriously. But as soon as the Ferrari-developed 90-degree V8 fires into life it's obvious the Maserati is a flightier, more highly-strung machine than the laid-back Jag.

Cruising at a ton in the XKR equates to just over 2500rpm. In the 4200GT the tacho needle is pointing vertically at 4000rpm. Since it revs to 7500rpm this elevated cruising gate is relative, but the engine is also more vocal and less well isolated, so you're constantly aware of the motor's work rate. The trade-off is almighty 6th gear acceleration, the like of which you'd have to slot fourth in the Porsche or kickdown in the XKR to match. It really does leap forward with shocking vigour, and although we never summoned the nerve to verify it, the 176mph top speed seems all too believable.

While there's no question the Maserati is the swiftest straight-line machine, questions are already being asked about its chassis. Expansion joints thump through the car like gunshots, and if encountered mid-corner the whole car skips and shimmies momentarily, where the Jag simply steamrollers them into submission. Even the 911 copes more convincingly, despite dynamics honed for hooning rather than schmoozing. In fact it nearly matches the XKR's compliance, if not its unconstrained muscularity, as we discover when I swap to the Porsche for the final motorway stint before we turn off the autoroute at Orange and head for Mont Ventoux.

With every generation of the 911, purists bemoan the gradual softening of its character, but I reckon there's method in Stuttgart's madness. I'd love to attack Mont Ventoux in a 964RS, but the drive from Calais would require a box of Nurofen meltlets and emergency roadside chiropractic manipulation. Even fitted with quasi race seats and a throaty sports exhaust, the C4S is a comfortable long-distance partner. It demands more input than the Jag or Maser but provides more stimulation whilst retaining some semblance of civility. It's not as comfortable to passenger in as the other two, but that's down to the optional sports seats. Swap them for more padded recliners and the C4S runs the more genteel GTs surprisingly close.

Poking some 6000 feet into the sky, Mont Ventoux is less than an hour from the autoroute. First used as a venue for a timed motor trial a century ago, the meandering mountain pass also plays host to a lung-bursting stage of the Tour de France cycle race. It's steeped in competition history, and is a special place for fans of pedal power and brake horsepower alike.

We approach the mountain from the south, passing through endless rows of vines heaving under the weight of plump, purple grapes. The road begins to head for the clouds miles before the actual start of the competitive hillclimb course, and our sense of anticipation and excitement increases with the gradient. Lurid graffiti smothers the road, evidence of last year's Tour, and as the vineyards give way to trees and rocky outcrops, the magnitude of the climb becomes apparent.

Lined with armco barriers, this looks more like the nadgety parts of the N΃¼rburgring's Nordschleife than a mountain road. It's fast too, long straights spooling away before us, climbing at around 30 degrees and feeding into inviting, just-blind combinations of lefts and rights. The camber always seems to be with you, but as you begin to fall into a rhythm a nasty hairpin always seems to trip you up.

As predicted, the Porsche is in its element, howling its approval up the straights, tucking neatly into the turns and giving maximum reassurance when indecision afflicts your right foot. It provides so much information through the steering wheel and thinly padded seat that you know exactly how much grip remains untapped.

The Jag is working hard in the rear view mirror, creeping up to the 911's fat tail on the straights, dropping back a little when the braking zones loom. Acting as point man is always tougher than following, but I'm still impressed to see the XKR doing so well. So too is its driver, John Hayman. 'The XK's evolved into a GT that can 'do' Europe and give its finest driving roads a right good bashing when it gets there. It storms out of bends with gobsmacking force and it also deals with the braking points brilliantly. Frankly, it carries ridiculous mid-corner speed for something of that size and weight.'

Just as we're beginning to really enjoy ourselves, blue flashing lights ahead call a halt to proceedings. A Gendarme is standing in the middle of the road, and as we cruise gently to a halt we are rather embarrassingly shrouded in our own brake smoke as the 911, Jag and Maser instantly barbecue their brake pads. Up ahead two of his colleagues are crouched by a stricken cyclist. No-one else is involved, but judging by the scarlet rivulets trickling from beneath the sheet things aren't good. 'Mort?' we ask. 'Mort,' the Gendarme replies. Gulp. Shaken, we continue past the scene of the accident, but our hearts aren't in a full-bore ascent so we decide instead to find a hotel for the night and raise a toast to the unfortunate cyclist.

Next morning we head out early and find the mountain deserted. I plump for the Jaguar.

With oodles of power and torque, enormous reserves of grip and plenty of feel, it's easy to settle into a very rapid pace without trying very hard at all. You don't even have to palm the auto gear lever around the J-gate, although the extra engine braking does give the Brembos a helping hand if you do. It's when you want to try that bit harder the Jaguar's limitations are revealed. Exiting the tighter hairpins the gearbox is fractionally slow to react, then as it kicks down the 4.2-litre V8 unleashes rather more grunt than even the 20in rear Pirellis can cope with and the inside wheel spins up like a Catherine wheel.

It's this reluctance to be hustled that holds the XKR back through corners where the 911 allows you to work beyond its limits and still feel like you're in charted territory. The XKR feels much more at home through fast corners, perfectly balanced and delightfully, minutely adjustable. For such a hefty car it's miraculous, so much so that it's almost churlish to point out that the C4S still trumps it for involvement and poise. The brakes are also man enough to stop the Jag repeatedly from serious speeds, although much like the steering, the pedal doesn't have the uncensored feel and firmness of the Porsche.

Ever since my early stint on the autoroute in the Maser I've been silently dreading putting it to the test on Mont Ventoux. You know within the first few yards whether a car is well sorted, and the 4200GT didn't feel at one with itself, even on the motorway. We're half way up the mountain now, and as I round one of the countless fresh air corners, the summit of Ventoux fills the windscreen. Crowned with a sinister space telescope and devoid of any vegetation, the rocky peak looks like part of a lunar landscape. Spooky isn't the word.

In the Maserati there's no time to gawp at the scenery. It really does go like the clappers, pulling hard to 5000rpm then searing on with renewed vigour to 7500rpm. Wringing out the 4200GT is a brutal process, each pull on the right-hand paddle hammering the next gear home with all the mechanical sympathy of a hardened hire car driver. It sends a shudder through the structure of the car and, even at more restrained speeds, emits a wince-inducing cog clatter that sounds like you've just run over a loose manhole cover. Maserati should try an M3 SMG to get some hints on how to do it properly.

Chassis-wise the 4200GT is an odd one. Crashy at low speed, the stiff ride never translates into confident body control, and the front and rear ends constantly fight with each other for your attention. Turn-in is rapid and grippy, but there's little feel to back it up, resulting in a tense, jumpy feel as you steer for the apex. Once powering towards the exit you can feel the tail load up, but the point at which the rear end begins to slide is masked, making the eventual breakaway swift and unforgiving. And that's in the dry. Driving hard in the wet is like walking on eggshells.

Interestingly, given the luxury of driving repeatedly around the same corner for photography, it's possible to discover that the Maser regains some composure and balance when steered on the throttle, but I'd trade this for more feel and some progression before the onset of a slide. Likewise some added stability under braking would be welcome, as any steering input while braking heavily can seriously upset the chassis.

The outcome of this test was never going to be black and white because by definition cars like this are more concerned with shades of grey. We'd expected the Maserati to play a numbers game, getting closer to the XKR's refinement and loping long-distance stride than the 911, then using its power and paddle-shift to push ahead of the Jaguar on the mountain roads. What we found was a car that displays a dismal lack of cohesion. A brittle ride and stressed high-speed cruising make heavy weather of the distance work, while snappy dynamics, a paucity of feedback and a frankly appalling transmission make the 4200GT Cambiocorsa a frustrating, intimidating experience on roads where it should be able and engrossing. There are fleeting moments of brilliance, and you begin to warm to the Maserati's flawed charms, but then the gearbox fumbles or the weather conditions deteriorate and you're reminded of just what an ill-sorted, unhappy car the 4200GT is.

We knew the 911 would be king of the hill at Mont Ventoux, just as we expected the Jag to cream the autoroute. What we didn't expect was the 911's lesson in how a lack of opulence doesn't equate to a lack of long haul comfort, nor the Jaguar's pace and poise when chasing the Porsche's tail. My heart tells me I'd rather have the 911, if only for its out-and-out ability on give and take roads. But the XKR does such a magnificent job of shrugging off a solid day's driving and then raising its game at Mont Ventoux that my head insists it gets the nod. On this very special journey the XKR proved to be the consummate GT.