The R has a Brembo brake package featuring 14.3-inch-diameter vented front discs, 12.9-inch solid rear rotors, and four-pot aluminum calipers. The power steering has been revised, while the suspension features stiffer bushings and retuned springs, dampers, and anti-roll bars. The R uses Jaguar's Computer Active Technology Suspension (CATS), which incorporates electronic control of two-stage adaptive dampers. Surprisingly, the R uses an open differential, because Jaguar engineers feel that most owners will be saved from wheelspin by the stability system. Finally, the natty wheels are shod with meaty 245/40 front and 275/35 rear tires.
On the roads of sunny southern Spain, the S-type R was a fine ride. The powertrain and suspension refinement are so good that you generally need to look at the speedometer to gauge your (often extreme) speed. It also rides really well: firm but not harsh, with surprising suppleness over broken pavement. Mid-corner bump absorption is excellent, too. Drive it as if it's a regular car, and you will hardly hear the engine and barely notice upshifts from the brilliant new automatic. Indeed, the only engine note is a strident supercharger whine, which becomes a bit annoying after the novelty wears off.
The R is speed-limited to 155 mph, and Jaguar claims it will sprint from 0 to 60 mph in 5.3 seconds, but its midrange performance is the most impressive feature. Bury your right foot, hear the supercharger kick in, feel the transmission downshift a couple of gears, and you can overtake with aplomb. Along Catalunya rally stages that would have been better suited to a Subaru Impreza WRX, I used the J-gate to stir the transmission between third and fourth gears, relying on torrents of torque to go very swiftly from one corner to another.
One of the S-type R's best features--something that definitely hasn't been stellar on Jaguars through the years, except on the original E-type--is the steering. There's more weight and feel than we're used to with a Jag, which allows you to take advantage of the nicely balanced chassis. Grip, as you might imagine from the width of the tires, is strong. The S-type R doesn't have the ultimate body control or connectedness of an M5 (and it will spin its inside rear wheel at will through second-gear corners), but the trade-off is a more refined highway ride than the BMW provides. The brakes are impressive, too, scrubbing off speed mightily with rewarding feedback.
Without a doubt, the R is a potent cross-country weapon, whether you're contemplating freeways or byways. An M5 is the more complete car for the enthusiast, but the Jaguar is extremely close. It also has a more inviting, less clinical cabin than the German car and is different enough to appeal to someone who wants lots of performance with a great deal of refinement and drivability. And to someone who wants an automatic transmission as well.