We’re just a few hours into this group test and already the Panamera Turbo is a rapidly disappearing blob on the horizon, metaphorically speaking. Usually we schedule the potentially damaging performance tests after the drive and photo shoot, but not this time, and we’re genuinely shocked at the figures it has turned in. They’re not just outstanding for a sports saloon; a decade ago they’d have been impressive for a full-blown supercar.

At the Panamera’s launch, Porsche claimed many attributes for its first saloon car, including class-leading efficiency, ride comfort on a par with a Mercedes S-class and, of course, Porsche-quality dynamics and driver satisfaction. The quoted figures for the range-topping Turbo looked pretty tasty, too, including 0-62mph in as little as 4sec dead, thanks to a unique combination of 493bhp from a 4.8-litre twin-turbo V8, a seven-speed dual-clutch ‘PDK’ gearbox and four-wheel drive. But we did better than that.

Initially we simply pointed the Panamera at the far end of Millbrook’s mile straight and snappily introduced the throttle to the carpet. From rest the Panamera hit 60mph in 4sec dead and 100 in just 9.1. Awesome, but it was just warming up. This particular car has the Sports Chrono option that gives a transient overboost, pumping torque up from 568 to 625lb ft, and also provides launch control. So hold the brake, press the throttle and the V8 settles at a grumbly 5000rpm. Now release the brake. A moment later the Panamera lunges forward, first and second gears are gone in a blink and it forges on, upshifting seamlessly, nailing 100mph in 8.9sec and, on the way, 60mph in a scarcely credible 3.6sec. Yup 3.6sec to 60mph, a time that would be impressive in a 911 Turbo or GT2, if they could manage it.

It was with a slight sense of anti-climax that we transferred the test gear to the cars we’d brought along to help define the Panamera. The Jaguar XFR is our current favourite big sports saloon and boasts a Panamera-pipping 503bhp plus a finely struck balance between ride comfort and handling alacrity. The upcoming new XJ is a more obvious rival in terms of size, price and pitch (see page 94) but it’s a few months off. Mind, if the Porsche wants to claim dynamic precedence in this class, it needs to beat the XFR. And the Maserati Quattroporte, still the most handsome and spacious sports saloon bar none, and a great mover too.

The Quattroporte’s handsome looks appear undiminished by time and this S version is powered by the lustier 4.7-litre V8, but here it’s substantially out-gunned. With natural aspiration it musters 425bhp at 7000rpm but only 361lb ft at 4750rpm, and at the weigh-in it recorded the highest kerb weight, a full 2068kg, against the Porsche on 2004kg and the Jaguar, which casts the smallest shadow, on 1974kg.

Maserati claims a 0-62mph time of 5.4sec for the QP S and our 14,000-mile test car more than lived up to that, posting a two-way average of 5.1sec and knocking off 100mph in 12.1sec. Decent times for a big, two-ton auto saloon but not outstanding in this company. Although lacking the Maserati’s advantageous weight distribution (49:51 front:rear), the Jaguar’s extra muscle is exquisitely exploited by its traction control and it stormed the mile straight, hitting 60mph in 4.8sec and 100 in a blistering 10.2sec.

And so to the challenges of the Bedford Autodrome. Naturally, in the Panamera we select ‘Sport Plus’ for the stiffest of three damper settings and the keenest throttle/gearbox response, and it’s mightily effective. There’s terrifically strong drive out of slow corners and tireless braking from the (optional) carbon brakes, but we end up disabling the intrusive PSM (Porsche Stability Management). The rear becomes surprisingly lively under power and turning in on the brakes, but it’s catchable and exploitable (though we note that PSM is still stepping in occasionally in fast turns). A couple of laps are scuppered by the PDK ’box acting up out of the second-gear Bank Complex and offering second or fourth but not third (which is on the other ‘side’ of the ’box), but the final lap is a good one and a new saloon benchmark is set: 1.26.5, which lops 1.3sec off the previous class best, set by the Vauxhall VXR8 Bathurst S.

It’s when we switch to the Jaguar that we appreciate just how much drive the Porsche finds and how level its adaptive air suspension has been keeping it (this car also has Porsche Dynamic Chassis Control: active anti-roll bars that decouple in a straight line to improve the ride). The XFR feels tall and soft like a Range Rover and, having quickly disabled the nannying stability control system, it’s tail-happy like it’s running eel-skin tyres on a skid-pan. Using the adjustability this offers while at the same time maximising rear drive is the challenge, and what feels like the optimum lap comes in at 1.27.9.

With its crisp-sounding V8 kept up high in its sweetest spot, the Maserati feels brisk and agile, but it’s hard to decide if it’s better with or without MSP (Maserati Stability Program) engaged. It feels tidy and effective with it on, but proves quickest with it off. After a couple of flying laps the brakes are smoky and the pedal softening. It manages a best of 1.29.5.

As opening salvos go, the Panamera’s is devastating and raises the distinct possibility that you can have it all: top-drawer sports- saloon ability and first-class limo luxury. Well, maybe not all. There’s no way I’d describe the Panamera as handsome, though you’ll have your own opinion. In ‘Carrera White’ it’s not as bad as I feared, though the optional 20in ‘RS’ alloys help (19s are standard). There’s a sort of honesty about it that appeals, and not just to me; it attracts lots of interest, all of it genuinely positive as far as I can tell.
It’s a very big car, though, a car that makes it look like the tax disc has shrunk and the driver is child-size. Swing open the door and you’re greeted by a truly fabulous interior combining fine design with wonderful leatherwork and expensive-looking polished metal detailing. Strictly four seats only though.

Our choice of Cumbria as the venue for the photo shoot gives a good three hours of fast cruising in which to assess comfort and refinement, and the Panamera scores well, with very low levels of road roar and wind noise. Against this standard you notice the slight rustle of wind noise from the XF’s side window, while the Quattroporte sounds like a hatchback with the rear seats folded – slightly hollow with some tyre noise. They’re all very comfortable places to be, though, with fine driving positions, great seats and high quality sound systems.

However, there’s something a bit odd about the Porsche. Left in its default Comfort damper setting the ride is a little lollopy, slightly loose, and this, coupled with a very tall seventh gear (over 45mph per 1000rpm) and soft throttle response gives it what associate editor Ollie Marriage succinctly describes as a ‘sleepy’ feel. Press the Sport button and the damping sharpens up and PDK drops a gear, which feels more appropriately alert but is less economical. Press Sport Plus and it stiffens even more and drops two gears, with throttle response to match, which is rather too tense, but you can select any combination of the three damper and three gearbox and throttle response settings. Always, though, there’s an underlying feeling that body control is a little unnatural, which must be down to the air springs.

After cycling through all permutations it’s a relief to get into the Jaguar and find that there are no buttons and it rides just fine as it is. That said, we’ve already discovered that none of these saloons offers a limo-like ride over lumpy town roads. The Porsche’s wheels jiggle and its suspension sounds crashy. The Maserati, on the softer of its two damper settings, clatters into potholes, which send tremors through the shell. The Jaguar has a sharp-edged, resilient feel.

Time spent in the Porsche’s cockpit diminishes the impact of the XF’s narrower, clean-cut interior, but the Quattroporte’s spacious cabin, here in all black with glossy piano black details, holds its own. The perfect motorway ride probably sits between the Maserati’s two damper settings, though, there being a hint of float on the default setting and a bit of fidget in Sport, which rules itself out for restful progress because it can’t be uncoupled from a crisper acting throttle and a more eager, one-gear-lower gearbox strategy.

Full alert is what’s needed when we finally turn left off the A1 at Scotch Corner and a few miles later peel off the A66 towards Barnard Castle. The combination of light drizzle, narrow roads and the big Maserati isn’t the most promising, and yet just a couple of miles in it feels great. It was already apparent that the Quattroporte had the best steering here, the most natural, detailed and connected, but I never expected that the chassis would feel so good under pressure. The Maserati moves down the road in a wonderfully fluid way, with precision but also a reassuring calm, a poise that puts you at ease. It feels effortlessly in tune with the road rising, falling and turning beneath it, so you’ve soon forgotten its scale and you’re urging it along like you would an M3. As we climb and the road gets more challenging, the Maserati doesn’t need to slacken its pace; just the occasional shudder through the body and schrik! as the vestigial front mudflaps meet asphalt betray the effort.

We’re high above a scenic river valley when a suitable changeover spot appears. I’m keen to see what the Porsche makes of this road. You seem to drop into the Panamera’s seat more than in the other two, the higher facia and window line enhancing the low-slung feel. There’s a reassuring solidity to the structure, an impressive polish to the controls – this is a good place to be. Except that the car feels out of sync with this difficult road and its random lumps and cambers. There’s a strange elasticity to the suspension movements in the softest damper setting – it’s held in tighter check by the stiffer settings but the feeling never quite disappears – and the Panamera occasionally feels wrong-footed. Worse, there’s no steering feel whatsoever, so you’re unsure exactly what’s going on. The nose turns keenly, no question, and it hooks up brilliantly, allowing full throttle ludicrously early, all four wheels harnessing the enormous torque of the twin-turbo V8, but it does rather feel like you’re a passenger.

The Jaguar is much more transparent, more like the Maserati, only with what feels like an extra inch of throttle travel. Neither the Jaguar nor the Porsche’s V8 sounds as pure and musical as the Maserati’s, though the supercharger that adds a gritty edge to the Jag’s 5-litre also moves its performance up a step. The XFR has a narrower tracked, less naturally planted feel than the Quattroporte and steering that’s a fraction less lucid, but it’s a car that flows effectively across the ground. When there’s the opportunity, it piles on the speed just as energetically as the Porsche, feeling lighter and more nimble. A look at the performance figures later reveals that from 60 to 150mph, the XFR is just 0.6sec slower…

The road out of Alston down to Penrith is smoother and wider and suits the Panamera better, but it also suits the others rather nicely too. Settled at a canter, enjoying the vast, late- afternoon views, the Jaguar feels in perfect harmony with the road, its paddle-shift ZF auto responsive and wonderfully smooth and its brakes feelsome and keen as it weaves down through the twists and turns with an easy accuracy. Oddly, the Maserati feels a bit less polished and looser when it’s not under pressure, but it still has an agility that belies its scale. The Panamera is comfortable and accurate but still feels numb.

Filling up before heading back up to the top to catch the late afternoon sun reveals that the Panamera has been the most fuel-efficient. With the best aerodynamics, that seven-speed PDK transmission and stop/start technology, it is claimed to be class-leading, though here its margin over the others is small: it has returned 15.5mpg compared with 14.5 for the XF and 13.4 for the Quattroporte.

Chasing back up to the Hartside café, I’m in the Quattroporte and Ollie is behind in the Panamera. The Maserati reaches the top without once holding up the Porsche. ‘I expected it to be easy to stay latched to the QP’s rear bumper,’ says Ollie, ‘but that wasn’t the case. I couldn’t believe how well the Maser was moving up the road.’ Behind the wheel, the Maserati felt brilliant: willing, responsive and precise. Paddle-shifting between second and third gear, keeping its V8 howling between 5000 and 7000rpm, it flowed from corner to corner on exactly the line steered, diving in like a car half its size and considerably lighter, the rear shifting subtly under power.

That’s how the Porsche should feel, but it doesn’t get close. Once again it felt its weight and, despite having the grip, power and traction, it couldn’t summon the agility. It didn’t help that, as at the track, the gearbox couldn’t find third gear on a couple of occasions, but even if the Panamera had been looking for a way past the Quattroporte for the whole of the climb, it would have been a hollow, technical victory.

The most disappointing thing about the Panamera Turbo is that it doesn’t engage, inform or involve its driver in the way that the Jaguar and Maserati do, or the way that the Boxster, Cayman and 911 do. It is numb and unsettling, mostly because of its air suspension, it seems, perhaps partly because there is drive through its front wheels. The Panamera of choice has to be the normally aspirated 394bhp two-wheel-drive S with its brighter, cleaner steering and purer dynamics. But the driver’s sports saloon of choice isn’t a Porsche at all. It’s the multi-faceted XFR or, if you fancy something a bit bigger, the suave Quattroporte S.

Following the successful start of the Panamera into the market, Dr. Ing. h.c. F. Porsche AG, Stuttgart, is rapidly expanding the range of models available: Starting in May 2010, both the Panamera and the Panamera 4 will be at the dealership as the new entry-level versions leading into Porsche’s Gran Turismo model series.

Both models are powered by a brand-new 3.6-litre V6 featuring Direct Fuel Injection and developing maximum output of 300 bhp (220 kW) plus peak torque of 400 Nm/295 lb-ft. Following Porsche’s nomenclature, the Panamera transmits its power to the road via the rear wheels, while the Panamera 4 comes as standard with active all-wheel drive.

The two new versions of Porsche’s Gran Turismo are convincing examples of the Porsche Intelligent Performance consistent development strategy. Equipped with PDK Porsche-Doppelkupplungsgetriebe (Porsche Double-Clutch Gearbox) and Auto Start Stop, both models consume far less than 10 litres of fuel on 100 kilometres in the New European Driving Cycle: The Panamera makes do with a mere 9.3 litres/100 kilometres (equal to 30.4 mpg imp), the Panamera 4 averages 9.6 litres/100 kilometres, equal to 29.4 mpg imp. Nineteen-inch all-year tyres with optimised roll resistance available as an option reduce these consumption figures by another 0.2 litres/100 kilometres, giving the Panamera a CO2 rating of just 213 g/km, the Panamera 4 an equally impressive 220 g/km. Both V6 versions of the Panamera fulfil the strict EU5 emission standard in Europe and the LEV standard in the United States.

Superior economy and performance typical of the brand do not rule out each other on these new V6 Gran Turismos. On the contrary – the ideal combination of these qualities is attributable to consistent lightweight construction as one particular highlight, with the axles, doors, engine compartment lid, wings and the rear lid all made either of aluminium or a combination of aluminium and magnesium. At the same time the brand-new V6 power unit built at Porsche’s engine plant in Zuffenhausen and boasting a 90o cylinder angle is approximately 30 kg or 66 lb lighter than the eight-cylinder featured in the Panamera S and 4S, thus contributing to the low overall weight of the Panamera of just 1,730 kg or 3,815 lb.

Like the proven V8 models, both the Panamera and the Panamera 4, as genuine Gran Turismos, combine sporting character with a high standard of comfort and everyday driving qualities. Apart from the regular steel suspension available as an option with variable dampers, adaptive air suspension with additional air volume is also available on request. This provides a very wide range of suspension qualities and features extending from an even higher level of motoring comfort at one end all the way to extremely sporting driving dynamics at the other.

The Panamera and Panamera 4 will be making their world debut at the Beijing Motor Show as of 23 April 2010. Both models will be entering the German market in May 2010 and are scheduled to enter the US market in June.

Prices start at Euro 75,899.- including value-added tax and national specifications for the Panamera (base price in the Euro countries Euro 63,600.-), while the Panamera 4 fitted as standard with PDK Porsche-Doppelkupplungsgetriebe retails at Euro 84,110.- including VAT and national specifications (base price Euro 70,500.-).