WEAPONS INSPECTION

Weapons Inspection. Autocar 25 Feb 2009.

We know that Jaguar's XFR is an awesome super-saloon, but can it eclipse the BMW M5? Andrew Frankel fires up the V10 to find out.

Drive this new Jaguar XFR hard and fast for a day and the indelible imprint it  leaves on your mind is not one you might anticipate. It's not how quick it is, although it is very, very quick. Nor is it how well it handles, despite its superb handling. It is that it's been a long time coming. This is the Jaguar saloon theworld has been waiting half a century to see.

Back in 1959, Jaguar shovelled its 3.8-litre motor under the bonnet of the beloved Mk2 to create its first real hot saloon, and the way it combined dazzling pace with innate good manners earned it bragging rights among the legends of Jaguar's road car heritage. But it never followed it up convincingly. Until now. At last Jaguar has another, every bit as deserving today as the 3.8 Mk2 was five decades ago. Like I said, it's been a long time coming.

To see Jaguar's achievement for what it is, you need something to provide perspective – something like the best super-saloon currently on sale. Hence the brooding presence of BMW's M5 on these pages. On paper these cars are closely matched on price, power, performance and positioning. In reality, and as we shall see, they have very different flavours, and whatever you go on to read in this test, know first that neither makes the other irrelevant. One will win, the other will lose, but both will remain fully deserving of their place in the hearts and minds of super-saloon fans.

A quick run up into the hills of Andalusia in the M5 shows clearly what the XFR now faces. With its V10 motor and seven-speed, paddle-operated manual gearbox, its powertrain seems more advanced than the old-school V8 auto approach on the Jaguar.

And once you've pressed the power button by the gearlever and unleashed its 500bhp, you'll know that the M5 has lost none of its bite. For a four-door saloon, the manner in which it delivers its full performance potential is almost indecently aggressive. Truth is, at the 6000rpm at which the Jaguar hits peak power, the BMW is just getting into its stride. And the sound of this motor on the far side of 8000rpm is not something anyone who has heard it will easily forget.

The price (and it's a real one) is that with peak torque of 384lb ft way up at 6100rpm, if you need to use its full performance then you have to keep it spinning in this band. And if your job is trying to keep up with an XFR, please believe that you will need to.

The most significant number in relation to Jaguar's all-new V8 motor is not its 503bhp, or even its 461lb ft of torque, but the fact that this fat wad of twist is not only available right down at 2500rpm and is also all hanging about at 5500rpm. There would be more too, but it would melt the gearbox and so is artificially restrained.

Because the engine is quiet – quieter than both the M5's motor and the supercharged 4.2-litre V8 in the now-defunct XF SV8 – it feels more effortless still. Some, myself included, would want a little more of an aural occasion on full throttle, but if the XFR is truly to split its role between that of sports saloon and grand tourer as Jaguar claims, then perhaps there is something to be said for speaking softly, not least when you wield a stick as big as this.

Jaguar claims that the only fully automatic car on sale capable of beating the XFR's 1.9sec 50-70mph time is a Mercedes- Benz SLR McLaren, yet this performance (along with a sub-5.0sec 0-60mph time and a sub-10.0sec 0-100mph run) is delivered with so little fuss that it's hard at first to believe the numbers appearing on the clock. Confirmation only comes when you look in the mirror and see just how small the M5 has become.

In fairness, this ability to put clear air between itself and the M5 has more to do with the difficulty of keeping the M5 in the right gear to cover its relative absence of low-end torque rather than any lack of ultimate pace. But during the day the Jaguar was continually distancing itself from the BMW, proving by far the more effective overtaking weapon and, in the real world, the significantly quicker car.

Nor should Jaguar be criticised for failing to provide a DSG-type gearbox or an electronically actuated manual like that in the M5. In fact, the Beemer's unruly transmission is as close to a bum note as the M5 strikes.

By contrast, the ZF auto in the Jag is beautifully controlled and outstandingly quick when changes are dispatched by paddles. It understands implicitly that an engine with that much torque should, so far as is possible, be left to get on with it. So while you need to spend time hunting around for the right ratio in the M5, in the XFR you just flick the transmission into fourth gear and leave the engine to carry you along on a great elastic wave of torque.

But you'd don't need to spend long back in the M5 to be snared by it once more. It's a much more enthusiastic car than the XFR, and makes greater efforts to involve you in what it does. Some will find the provision of so many different tuning choices – from the power of the engine to the mapping of the gearbox – a pointless and puerile complexity of interest only to technogeeks, but I've never found them intrusive. We all have different moods when we drive and having a car you can adapt to suit each one strikes me as basic common sense.

Besides, M5s of all descriptions and high-performance Jaguar saloons from the original XJR onwards have been meeting on these pages for years, and flawed though my memory undoubtedly is, I can't remember the coin ever falling Jag side up.

But perhaps today was going to be different after all. For as the miles flew under its wheels, so too did I feel something in the M5 I don't remember from any of happily many previous encounters: its age. There is no helping this; nor is there any avoiding the fact that the M5 has already seen its third birthday and the car on which it is based is five years old. And it was equally obvious that this passage of time would never have been so apparent were it not for the presence of the XF. The only surprise was that where the XFR made the M5 seem oldest of all was in the corners.

This is where Jaguars have always suffered. The perceived need to keep their suspension soft and the absence of a limited-slip differential between the rear wheels of even the most powerful Jaguars have always capped their dynamic ambitions. No longer. By adapting a mechanically locking diff that started life in the Range Rover, and by using electronics to vary the degree of that lock from zero to 90 per cent, Jaguar has finally (if you'll forgive the pun) unlocked the full potential of the XF's chassis.

Its springs are 30 per cent stiffer than the SV8's, its roll bars are thicker and the old CATS adaptive damping system has been binned in favour of an all-new arrangement that, instead of providing just a small number of preset damper strategies, can work at will within a vast range, continuously varying its control of roll, pitch and heave according to need.

The news is not all good; even the best limited-slip diffs promote understeer at low speeds and this one is no different. Try to exploit the extra traction provided by the diff when coming out of a slow corner and you'll feel the nose push wide of the apex, a characteristic you'd not find to anything like the same extent in this car's true parent, the ugly but largely underrated S-type R.

But there's nothing, save making a spectacle of yourself, to prevent you from turning off the electronics and invoking the V8 to break traction at the rear in order to restore grip at the front, something that the XFR will do with great willingness and no little drama, as long as someone else is paying the tyre bill.

But it is at perhaps a more realistic work rate that the XFR comes into its own. Over the wide open, sweeping roads of southern Spain it demonstrated a composure I would not have credited to a near-1900kg saloon had I not been there to see it for myself. The precision with which it could be guided, the delicacy with which it could be adjusted and the sheer muscle-wilting grip that its fat Dunlops could generate will live on in my mind for some time to come. Its steering, in particular, is magnificent.

The BMW's answer to this is pure M5; it's a more frenetic performer, offering big excitement, but not always for precisely the right reason. At low speeds it is still a born entertainer, with a more neutral chassis balance than the XFR. But as you up the pace, so you have to work harder to stay with the XFR through the turns, not because the M5 lacks grip but because there is less clarity of feel in both the steering and chassis. When the road starts to undulate or the surface begins to ripple, there's a touch less raw body control too. Make no mistake, there is as much fun to be had in the M5 as the XFR on such a road because it is such a maximum-attack performer, but you'll need to work harder to achieve it. Only under braking is the M5 consistently superior to the XFR.

But perhaps the single most impressive aspect of the XFR is how Jaguar has set new class standards of dynamism and driving pleasure without perverting its role as a long-distance touring machine. It rides more firmly than any Jaguar saloon in history, but still that ride is not harsh – and that, sadly, cannot always be said for the M5. The BMW counters with a substantially more spacious interior (if you have more than one grown-up passenger to carry on a regular basis, take a long, hard look in the back of any XF before signing), though their boots are the same size.

You'll know already that this test does not end in the same way as previous Jaguar and BMW showdowns in this magazine. No more is the Jaguar the plucky loser; no more do we have to point to its charming character to make up in part at least for its dynamic shortcomings. Fact is, the XFR wins this test and wins it well. Though the figures don't show it, it's quicker in a straight line than the M5 and more fluent through the corners. It is at least as much fun to drive and a damn sight easier to enjoy. And when it's time to wind down and go home, it's quieter and more comfortable. All this without even mentioning that it's prettier and cheaper, too.

Even so, the BMW is not humiliated or even humbled here. If you want a car that needs taming, if rough and ready is more to your taste than smooth and sweet, get the M5 with our blessing. It is what it has always been: a fine and thrilling machine that just happens also to be an effective family holdall.

But it can't beat the XFR. The world may have had to wait half a century for Jaguar to build another world-beating super-saloon, but having driven the XFR long and hard, I can state with confidence that the wait is now over.