The latest addition to Jaguar's fleet at its Nrburgring Nordschleife engineering test centre is the marque's very first taxi, albeit one with rather more ability than you may expect from a traditional cab; based on the latest all-aluminium long wheelbase XJ Supersport with Sport and Speed Pack options, Jaguar's 'Nrburgring taxi' boasts 510PS from its 5.0-litre supercharged V8 engine and a top speed of 174mph, but no fare meter

Said Frank Klaas, Global Head of Communications, Jaguar Land Rover: "We've been running a successful Nrburgring driving programme from our Nordschleife engineering test centre now for some time, as it's the very best place to demonstrate the dynamic abilities of the current Jaguar XF, XJ and XK models.

"Of these models, we found it's the XJ Supersport that most often surprises journalists with its speed simply because they perceive it to be a large luxury car. The XJ is both those things, of course, but its aluminium architecture means it's rigid and lightweight too, which make it a very good car on track. To underline that fact, our engineering team created this special Nrburgring taxi version in which our trained drivers can safely take passengers on very hot laps!"

Finished in non-standard matt grey paint with exterior Sport Pack, the Jaguar Nrburgring taxi is also specified with the Speed Pack - which raises its electronically limited top speed from 155mph to 174mph - but is otherwise mechanically standard. Inside there is, of course, ample room for four, although a few of the XJ's usual creature comforts have been replaced in order to keep its occupants securely in place during the very quick laps of which it is capable. Gone are the standard leather-trimmed heated and cooled seats, and in their place are four race seats, each equipped with four-point harnesses. A full bespoke roll cage completes the interior changes.

The performance-driven Sport and Speed Pack options were introduced for the XJ range earlier this year for both standard and long wheelbase models.

The interior Sport Pack adds optional sports front seating with the rear seats trimmed to match, along with additional discreet detail changes.

The exterior Sport Pack adds a front splitter and extended bootlid lip to maximise aerodynamic stability at high speed, while complimentary aesthetic changes include red brake calipers, a gloss black finish to the front grille andlower air opening and side vents, and 20-inch 'Venom' five-spoke alloy wheels with a diamond-turned sparkle silver finish.

The Speed Pack - only available on Supersport models specified with the exterior Sport Pack - raises the electronically limited top speed from 155mph to 174mph via a recalibration of the engine management system.