Senin, 23 Maret 2009

Running With the Big Dogs
By Alistair Weaver, European Editor Email
Date posted: 02-24-2009

The 2010 Jaguar XFR sneaks up on you. You have to drive with one eye on the speedometer, cross-checking your perception of speed with the reality displayed in black, white and red. The XFR is not a raw-edged racing sedan; it's a supercharged 510-horsepower express that baits the BMW M5 with its sheer sophistication.

The Jaguar XFR is a fast, beautiful and very British challenge to the hegemony of German sport sedans, good enough to makes moustaches quiver in Ingolstadt, Munich and Stuttgart. If the introduction of the XF sedan last year woke Jaguar from its self-induced slumber, the 2010 XFR gives it a potent shot of caffeine.

With the 2010 Jaguar XFR, the guys at Jag have finally delivered the car they've been promising ever since Ford began pumping money into the company in 1990. It's ironic that new owner Tata Motors will be the one to get the credit.

As Always, It Starts With an Engine
It's been a long time coming, but the new 5.0-liter Jaguar V8 is finally with us. A naturally aspirated example will follow soon, but it's the supercharged version that concerns us here. It might be known as the AJ-V8 Gen III, but this is effectively an all-new motor with just two parts shared with the old 4.2-liter V8. The key technology in this R-Type application is direct injection, variable valve timing for both intake and exhaust, twin intercoolers and the latest Roots-type, twin-vortex supercharger.

Turbochargers have been in the news a lot lately, especially with BMW's decision to implement the technology in its street cars, but a new generation of supercharger technology has also recently arrived. Jaguar chose to continue its past work with supercharging in the interests of throttle response, efficiency and packaging. Now that AMG has largely abandoned the Kompressor, the use of supercharging also gives the Jag a key point of difference compared with its German rivals. The new engine is mated to the familiar ZF 6HP28 six-speed automatic, although it's been uprated to cope with the extra thrust.

And the thrust ratings are certainly impressive, as the Jaguar engineers targeted 500 hp in the belief that this is now a prerequisite for entry in the hyper-sedan club. To this end, the 2010 Jaguar XFR's supercharged 5.0-liter V8 offers up 510 hp between 6,000 and 6,500 rpm, with 461 pound-feet of torque between 2,500 and 5,500 rpm. This compares pretty impressively with the Audi RS6's ratings of 580 hp and 479 lb-ft of torque, the BMW M5's output of 500 hp and 383 lb-ft of torque and the Mercedes-Benz E63 AMG's 507 hp and 464 lb-ft of torque.

Get Down the Road
Those figures are impressive, even in a car that weighs 4,169 pounds. Jaguar claims the XFR gets to 60 mph from a standstill in 4.6 seconds on the way to the quarter-mile in 13.1 seconds. It accelerates from 50 mph to 70 mph in just 1.9 seconds and top speed is electronically limited to 155 mph. This is a thunderous car, and you don't have to work for the performance as you do in the naturally aspirated Merc or BeeEm. You rely not on the power but on the huge dollops of torque served up by the compressor.

This distinctive power production together with the superbly smooth gearbox is the key to the XFR sedan's stealthy performance. Plus the engine is so quiet that you're never aware that it's working very hard. Jaguar has all but eliminated the supercharger whine that always laid down a soundtrack to the old blown 4.2-liter V8, and the 5.0-liter V8 emits a deep, bass woofle that's never more than subdued. And just like the 2010 Ford Mustang and 2009 Ford Focus RS, there's a system in place to introduce engine sounds into the cockpit for a little more personality.

Nevertheless, this engine is actually too quiet. After all, if you've spent this much on a sport sedan, you deserve a bit of theater. The 2010 Jaguar XFR is another modern car that sounds better from the sidewalk than it does from the driver seat. Perhaps Jaguar might do well to offer an optional version of the new active exhaust system featured by the latest Jaguar XKR sports car.

A Sport Sedan That's Sporting
There are two significant chassis developments that the R-Type designation brings to the XF sedan: Active Differential Control (ADC) and Adaptive Dynamics. ADC is simply a differential that uses electronics to control the torque distributed to each wheel, operating only when required. The differential control works in conjunction with the stability control to manipulate the horsepower in all road conditions. It is hugely effective, enabling the car to pull away smoothly and cleanly with significant steering input, even on a wet surface.

Meanwhile, the Adaptive Dynamics system modifies the throttle and gearbox response depending on the way you're driving, while also altering the parameters of the continuously variable suspension damping. Put simply, it recognizes that you now want to play and will quickly switch to a more aggressive damping setting. As a result, you can take advantage of the suspension's comfort without having to sacrifice readiness for the fun zones.

Of course, this technology also makes the 2010 Jaguar XFR nowhere near as raw as an M5. The BeeEm demands your full attention, all of the time. The Jag isn't like that. The ride, while significantly firmer than a standard XF, is still pleasingly supple. Even with standard 20-inch wheels and tires plus a fast-acting steering ratio, the R-Type feels more sophisticated than the M-car. Yet this shouldn't be mistaken for a lack of talent, or ambition. The XFR sedan is stealthy, but still capable and entertaining.

The harder you try, the better it responds. You brake hard and deep into the corner (the front discs now measure 14.9 inches) to offset any initial understeer and then lean on the throttle pedal and ride the engine's torque. In high-speed corners, the XFR starts to feel lighter and smaller than it actually is, helped by crisp, accurate and well-weighted steering that's significantly better than that of the opposition. The six-speed ZF automatic is also an ideal foil for the V8, swapping cogs swifty with the aid of the shift paddles on the steering wheel and, in manual mode, refusing to change up without human intervention.

The stability control also has two modes: standard and track. In theory, the latter allows you to play a little, but it still intervenes strongly and relatively early. Of course, you can also turn the system off altogether, at which point the Jag can easily be tempted into glamorous, heroic powerslides, the sort of thing Jaguar development driver Mike Cross has spent a lifetime perfecting. The Jag XFR is much more amenable to oversteer than an M5 or an RS6. It isn't the Jag's default setting, but if you want to be a hooligan, it's happy to oblige.

The Look of Speed
The XF has been designed from the outset as a sport sedan, but the R-Type has given it an added dose of machismo. The chrome-mesh air ducts in the redesigned front fenders and the usual R-Type mesh grille are the most obvious visual changes that contribute to the car's aggressive new face. You'll also notice a deeper front bumper, louvers in the hood, extended rocker-sill skirts, a subtle spoiler on the deck lid, quad exhaust tips and of course the big 20-inch wheels inscribed with "supercharged." It's a comprehensive package that stays on the right side of tasteful.

The revisions within the interior are modest. You get discreet "R" badges on the steering wheel and fascia, a new twist to the aluminum trim, plus sport seats that move in 14 different directions. The only other tweak is to the instrument dials, which now boast a "supercharged" logo and a red needle. The Jaguar XFR remains a thoroughly nice place to be, even if there isn't as much room in the rear seat as you'd find in the Audi RS6.

The Price of Speed
The 2010 Jaguar XFR will come with a price tag of $80,000, which is a long way from the $52,000 of the entry-level XF sedan, but also a fair way below the supercharged $96,000 XKR coupe. Most important, the XFR sedan's price tag is $5,500 less than a BMW M5.

Just as with the XF sedan, the new R-Type probably won't get the instant badge recognition of a car from AMG, the M division or Quattro GmbH, but this new Jag deserves to run with the best. Handsome, massively quick and hugely capable, this car fulfills the XF's potential.

At last Jaguar is back in the game.