Few long-term test cars have proved more popular with those of us here at Autocar Towers than our Jaguar XKR.

There’s a good chance you’ll remember ‘BF56 LTE’ whether you’re a regular reader or not, because this was the bright red car that appeared on Top Gear TV.

Jaguar lent it to us for a year once TG had finished with it. And over the course of that year, the car covered more than 20,000 miles.

Looking back, I can’t remember a single serious complaint from anyone who drove it. The car was as fast as you’d ever want, wickedly sonorous, gloriously attractive to behold, it wasn’t ruinously thirsty and, best of all, it was comfortable. Comfortable to sit in; comfortable to ride in; quiet and absorbent over broken surfaces. It was the sort of car you’d happily drive 150 miles down the motorway just to get to that unforgettable B-road. And fast cars like it are surprisingly rare.

I was driven in that car’s replacement last week, and can tell you that the new 2009, 503bhp XKR will have a slightly different kind of appeal. As dynamic development expert Michelle O’Connor explained while we speared across the Warwickshire landscape, Jaguar has slightly altered the dynamic character of this car, partly because it has to, and partly out of choice.

“We stiffened the springs for this car relative to the last XKR,” she says. “We’ve quickened the steering and strengthened the chassis too, and we’ve fitted continuously variable dampers.”

“Now that it’s got 500 horsepower, this is a much faster car than the last XKR, and needs better body control. 500bhp is also like a line in the sand though, as we see it. People who want a car with more than 500bhp expect a slightly more hardcore experience than they might have got in the old XKR.”

Michelle went on to say that the new, 380bhp, normally aspirated XK will be a closer spiritual successor to the old XKR, while the new supercharged car breaks new ground for Jaguar. Even riding in it you can tell as much. There’s still comfort and compliance in its springs, but not as much. There’s much better vertical body control, but almost none of the brand’s trademark ‘glide and float’.

“The dampers are infinitely variable,” O’Connor tells me. “They calculate the necessary resistance at each corner in any circumstance, rather than reacting or ‘guessing’.” Sure enough, as we hurtle down one of Jaguar’s test route, I can feel the dampers tightening as we crest and dip, and then slacken when the road and the steering wheel straighten up. Potholes are dealt with effectively, but not quite as serenely as in the old car.

The engine note of this car is different; not quite as fruity as the last XKR, but bigger, stronger. This car’s got an electronic limited slip differential, and a more sophisticated DSC traction control system too. It’s faster, more focussed, and doubtless more rewarding at eight and nine tenths – and yet still easy to drive quickly.

My only regret is that the new XKR may not be as sweet as a day-to-day driver as its direct antecedent – and I’ll be waiting to see if our first drive verdict confirms as much next month. I’m not saying it isn’t a great driver’s car; I’m sure a new group of customers looking for a Jag to really mix it with the fastest road cars out there are going to love it. I’m just not so sure that I’m going to be among them.

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