If you’re looking at the Jaguar XJL Supersport with possible  acquisition in mind, chances are pretty good that you have a little  string of initials after your name, attesting to your economic status.  Initials like CEO, or COO, or (most probably) CFO, for example. One  glance at the price tells you this car isn’t exactly everyday  transportation. Possession sops up mass quantities of disposable income,  and it’s possible—likely, even—that if you have the wherewithal to  seriously contemplate ownership, you may also be thinking about  retaining a chauffeur.
That may be okay for trips to and from a  corporate HQ in a heavy urban setting. The L (long-wheelbase) version of  Jag’s revitalized XJ sedan adds about five inches to rear-seat legroom,  so with the exception of headroom there’s plenty of space back there,  as well as trays that drop down from the backs of the front seats. You  can relax, check your email, text, contemplate documents, and plot  corporate takeovers.
But trust us, you do not want to deprive  yourself of piloting this superb conveyance. Although we should add this  warning: The experience is seriously habit-forming.
Bureau of Statistics
As  noted, the L stands for Long: That extra rear legroom translates to the  wheelbase—which grows from 119.4 inches to 124.3—and an equal stretch  overall, from 201.7 to 206.6. Width (74.6 inches) and height (57.0) are  the same for long-wheelbase and standard XJs. Those dimensions are more  or less in the middle of this Jag’s direct competitors, all of which  have German accents—the long-wheelbase Audi A8, BMW 7-series, and  Mercedes’ AMG S-class offerings, the S63 and S65.
This is a substantial car, and size inevitably adds up at the scales.  Our test car weighed in at 4412 pounds (a standard-wheelbase XJ  Supersport we tested weighed 4316 pounds). Though it’s no wraith, the  big Jag is among the trimmest of these CEO sedans, some of which—we’re  looking at you, Mercedes—make the scales creak at around 5000 pounds.  Credit extensive use of aluminum in the XJ’s skin and chassis on this  score.
Power Play
All members of the new XJ lineup  share the same 5.0-liter V-8, offered in naturally aspirated (basic) and  supercharged versions. There are two levels of the latter, and the most  potent of them—510 hp, 461 lb-ft of torque—propels the Supersport  edition. (Compare that to the Supercharged-badged car, which makes 
only 470 hp, and the naturally aspirated V-8’s 385 hp.)
The  Jag’s six-speed automatic, and its gimmicky dial-a-mode shifter, is  upstaged by the seven- and eight-speed autos offered by the 
Deutsche-mobiles. It allows manual shifting via the paddles that have become 
de rigeur in today’s performance automatics, but the shifts could be a bit quicker, and the Germans’ transmissions are smoother.
Nevertheless,  when summoned to full thrust, the Jag’s supercharged V-8 delivers  eye-opening sprints: 0 to 60 in 4.2 seconds, 0 to 100 in 9.6, 30 to 50  in 2.2, 50 to 70 in 2.7. As to the other supercharged XJs, a  short-wheelbase Supersport hits 60 in 4.1 seconds, while an XJL  Supercharged hits that mark in 4.4. Quick pretty well describes them  all.
What’s the secret? The aforementioned low-for-its-class curb  weight, for one. Rip-tide torque with a curve that resembles the  topography of Nebraska—essentially flat from 2500 to 5500 rpm—for  another. This delicious rush could easily induce the Little Old Lady  from Pasadena syndrome: you can’t keep your foot off the accelerator.  Hard to explain to cops.
Read More: 
http://www.caranddriver.com/reviews/2012-jaguar-xjl-supersport-test-review