In the best of times, launching a luxury sedan against the likes of the BMW 5-series and Audi A6 would be a scary proposition, and these aren't the best of times. The XF lands just as the U.S. economy is in a flat spin, premium gas is hitting $4 a gallon and the luxury car market is falling on its posh butt...article continues.....

Meanwhile, in the very same month as the XF launch (March), Jaguar and Land Rover were all but acquired from Ford by India's Tata Group, an event that, with its empire-strikes-back overtones, has backlit the brand with an aura of decline.

The good news is that the Tata Group, which will pay $2.3 billion for Jag and Land Rover when the deal is approved later this year, will invest heavily in them. Just last week, Tata hinted that Jag would field a sports car to take on Aston Martin. That can only mean a modern-day E-type, a car Jag enthusiasts devoutly wish for. Meanwhile, Tata has committed to keeping production in England, treading lightly on the company's current management and generally honoring the Britishness of this quintessentially British brand. More good news: Jag's quality is vastly improved, and its customer service was tops in J.D. Power's 2007 survey.

The bad news: Jaguar, which has wandered the wilderness so long, will wander awhile longer. Which brings us to the XF.

The XF is a very fine motorcar in a market segment that demands utter perfection; it's a reasonably attractive sedan from a company that needs a ravishing, wallet-emptying beauty.

On this second point, I don't think there's much disagreement. You can call the XF "handsome," say it's purposeful rather than pretty, admire its well-planted stance. The glass-to-sheet metal proportions, the sinuous profile, the glossy encapsulation of the body all work. The roof pillars are slim, almost delicate.

But the front of the car — where the poetry of a brand resides — is kind of a mess. The molded mesh-like grille just seems to float there, unconnected to the fluting on the hood (which ideally would suggest contrails streaming back from the grille perimeter).

Jag's chief designer, Ian Callum, argues that he wanted to make a clean break from the previous model. I suppose. But, just as an experiment, readers should pick up a Sharpie marker and draw Jag's traditional upright-oblong grille — like the one from the outgoing S-Type, and the original R-D6 concept — onto the XF's picture.

There's a technical problem in the XF, too, and that's the large gap in the hood over-slam, especially around the headlights. Apparently the problem arose because of an outdated French motor vehicle requirement that owners be able to change the bulbs in the headlamps. In any event, it makes the car look as if the hood isn't closed.

If that seems like a lot of bother over the grille, well, Jaguar isn't Subaru. The Jaguar brand is an ongoing narrative of motoring enchantment, whose solemn code is "beautiful, fast cars." In a world full of BMWs, Mercedes-Benzes and Audis (and Infiniti, which makes perhaps the best car in this class), Jag has no place unless it is — as the ad campaign says — gorgeous.

The XF comes in three flavors: Luxury ($49,200) or Premium Luxury ($55,200), both powered by a naturally aspirated version of the company's 4.2-liter, 300-hp V8; or the Supercharged ($62,200), which is comprehensively equipped and, with 420 horses in harness, seriously quick (0-60 in 5.1 seconds). The Supercharged version comes with 20-inch wheels standard. In order to preserve the close-fit look between the wheels and the fender wells in the naturally aspirated models, Jag stylists dictated that the 18- and 19-inch wheel-and-tire sets (standard and optional) should have the same rolling diameter of the 20-inchers. The net is that all three cars have the deep-set, ready stance that big wheels provide.

Mechanically, the XF is a sedan version of the XK coupe/convertible. The chassis is the same (wishbone front suspension and multilink in the rear, with adaptive suspension on the Supercharged edition); the engines and transmission (six-speed automatic with manual shifting) are shared, as are braking, steering and major subsystems.

Like the coupe, the sedan is lushly quiet overall, feels big and powerful, and weighs a lot — 4,194 pounds in Supercharged trim.

That weight requires a more deliberate driving style than, say, a BMW. You can't just toss the XF into a corner unless you want to wildly chatter the stability control, but if you bend it into a long sweeper and squeeze the throttle, it turns in confidently and hangs on tenaciously. The S/C model has a Dynamic Mode in its stability control system, allowing drivers to slide the car around a bit more. It's fun.

The thing the XF Supercharged does best is to turn small holes in traffic into big holes with its thick band of thrust (408 pound-feet at 3,500 rpm). Go ahead, kick that mule. The supercharger whines, the comfy leather seat grips you tighter and the XF surges as if surfing a wave of warm English whiskey.

The commonality between XK and XF programs freed up time and development dollars to focus on the sedan's interior, which is full of nuance and invention, probably the most striking interior since the redesigned Cadillac CTS.

So far, XF sales have been good. The company has had more than 4,000 pre-orders — a major step in the right direction.

Here's what needs to happen now: Jag has to have a V-6 or diesel option at this price point, and soon. The fuel economy of these thirsty V-8s is going to be a millstone around the car's neck.

The company needs to emphasize the XF's equipment level, which is quite generous for the price. And it needs to get working on a nose job.

Jag's got a pulse, but the patient isn't out of the woods yet.