The XFR is also quite lovely on the road. Heading north from Seville into the foothills of the Sierra Morena, we selected Dynamic Mode, a choice confirmed by a digitally rendered checkered flag in the driver-information display and one that results in more aggressive torque delivery, among other sporting responses. We also depressed Jaguar's now-signature rotating gear selector so that it could be dialed past its normal D-for-drive detent to the S-for-sport setting. Driven benignly, the XFR's differences from the stock car are subtle, but once the roads opened up, we noted the slightly quicker steering and the sharper chassis responses, the result of 30 percent stiffer front and rear springs and the Adaptive Dynamics active-damping system. And we certainly noted the instantaneous throttle response and the visceral way in which the 461 lb-ft of torque churns to the rear axle, where it's expertly distributed by the rear diff. The supercharger whine that marred previous Jaguar R cars has been replaced by enticing snaps and snarls from the exhaust at high rpm and a nice growl at start-up. In fact, the power delivery from this engine is so linear and progressive, and the soundtrack is so good, it's easy to forget it has a supercharger.
But then you come over a crest, and a long, empty stretch of one of the Sierra Norte Natural Park's expertly maintained roads opens up before you.
You hit the left paddle to downshift to third, and the crackle of the exhaust reverberates through the scrub oaks and pastures. The tach needle races toward 7000 rpm, and both the checkered flag and the number 3 in the driver display turn bright yellow, begging you to upshift. You oblige, the XFR leaps forward, and you realize that it's not just wishful thinking and the spirit of Sir William Lyons that are hurtling you toward the horizon, it is indeed a world-class supercharged powertrain and a perfectly tuned chassis. Jaguar's claim of a 0-to-60-mph time of 4.7 seconds seems believable. Quickly, very quickly, a decreasing-radius, downhill corner that cuts through a terraced wall of red-tinted rock comes into view, and the big front brakes - with fifteen-inch rotors - decelerate the 4169-pound sedan without fading. Who knew a Jaguar sedan could provide such thrills?