When Jaguar created the new XKR-S, it had a simple aim -- to build its fastest mass-produced car ever. The latest hyper-cat is based largely on the standard XKR, but promises even more exhilarating performance, thanks to lowered, computer-controlled suspension, tweaked engine-management software, and new computer-designed body panels that promise the aerodynamic efficiency of a salmon.
We took the XKR-S for a spin to find out whether this £98,000 beast is all it's cracked up to be.
Whoa, body form!
One look at the XKR-S is all it takes to realise that this car is focused on speed. Numerous tweaks to its bodywork are geared towards improving aerodynamic balance and preventing the car from lifting off when travelling at high velocity. The front end, modelled using fancy computational fluid dynamics software, features twin cat-style nostrils for extra cooling, a carbon-fibre splitter that deflects air underneath the car, and vertical side intakes that channel air along the car's side skirts.
The rear, meanwhile, rocks a new rear diffuser and a carbon-fibre rear spoiler above the boot lid, which work together to improve stability. Together, the front, rear and underbody tweaks are said to help achieve a 26 per cent reduction in lift, keeping the car more planted when hurtling along the tarmac at high speeds.
Nuclear power plant
That extra downforce is a real blessing, because, if there's one thing the XKR-S does, it's hurtle. The car uses the same supercharged, quad-cam, 5-litre V8 engine as the standard XKR, but Jaguar has tweaked it to within an inch of its life, so it now produces a quite monstrous 542bhp -- 40bhp more than the standard XKR. Coincidentally, that's the same figure generated by the legendary Jaguar XJ220.
Jaguar has coaxed this extra power from the unit by remapping the software that dictates how much fuel is injected into the engine. The company's also increased the quantity of exhaust gas flowing through the car's new active exhaust system. The system uses special flaps that open at high revs to help the engine breathe more easily -- and scream more loudly.
Finally, Jaguar's bolted on a Roots-type twin-vortex supercharger, whose sole purpose is to ram more air into the engine to achieve bigger explosions during the combustion process. The company says this unit is 20 per cent more efficient at creating additional power than the supercharger used in the XKR.
Shock and awesome
The end result of this added power is savage performance. The XKR-S will achieve 0-60mph in a blistering 4.2 seconds, and will carry on accelerating until it reaches a top speed of 186mph, which, on paper, makes it the fastest mass-produced Jaguar ever.
Numbers don't quite do justice to the sheer brutality of this car's acceleration. Nail the throttle and you'll swear you've just activated the afterburner in an F-16 fighter jet. The rear wheels seem not to push the car forward, but to pull the planet towards you at a frightening rate.
It's possible to extract this performance with ease. Simply leave the car in its ordinary 'D' drive mode and it'll do all the work for you, changing gears automatically as it approaches the red line. If you fancy playing more of an active role, you can twist the JaguarDrive selector knob to 'S' mode and rattle through the gears yourself, using the surprisingly responsive paddle shifters behind the steering wheel.
Whichever mode you select, you can be sure that the XKR-S will emit an exhaust note to match its acceleration. Bury the accelerator and it'll make a din that can best be described as the sound of a Tyrannosaurus Rex gargling hand grenades in a thunderstorm. It's a brutish, primeval bellow that, in conjunction with the car's epic thrust, will leave you whooping like a 12-year-old on a rollercoaster.
The XKR-S is startlingly agile. Push it hard and it'll thread its way through twisty B roads with great poise, gripping the tarmac as if its 20-inch P Zero tyres have sprouted claws.
The car acquits itself beautifully on a race circuit, too. Its prodigious power makes the longest of straights seem like tiny back alleys, the brakes inspire confidence, and even low-speed corners are a joy, thanks to a whopping 680Nm of torque, which simply catapults you from one turn to the next.
If we have one gripe, it's that the steering feels slightly too light, and doesn't seem to convey much information about the level of available grip until the moment that level has been exceeded. In these situations, the car has a tendency to oversteer, its tail end spinning out and attempting to swap positions with the front. The chassis is so well balanced, however, that an armful of opposite lock is all it takes to have you gliding sideways through a corner in total tyre-smoking control.
With such startling performance, you could be forgiven for thinking the XKR-S is something of a beast when driving in everyday conditions, but you'd be wrong -- it's extremely relaxing. The car's suspension seems to absorb imperfections in the road better than that of some everyday road cars, and it's quiet when cruising at speed.
This odd dichotomy is the result of Jaguar's new 'active damping' system, which uses a computer to monitor the car's vertical movement, roll rate and pitch rate 100 times per second. If you're tearing around a track, it'll progressively make the suspension firmer to reduce body roll. Drive a little more sensibly, and it'll progressively soften the suspension to increase comfort levels.
The system works brilliantly, transforming the XKR-S from super-taut race car to super-soft cruise mobile without the driver having to lift a finger. It knows what you need and delivers it to you on a plate.
While Jaguar has done plenty to increase the awesomeness of the XKR-S' performance and looks, it's done relatively little to improve the contents of the cabin. The car uses the same cabin technology as the standard XKR, so an 8-inch display serves as the gateway to all of the information and entertainment settings.
The user menu is extremely easy to navigate. Unlike many high-end cars, which use ridiculous joysticks, knobs or even mice that control an on-screen cursor, the XKR-S uses a resistive touchscreen. If you see an icon on the display, you select it the good old-fashioned way -- by prodding it with a meat stylus.
The XKR-S offers the same Flash-based user interface as seen in the XF and XK, and it's starting to show its age. It's well laid out, but the animated transitions between menus are jerky and far slower than we'd like. Switching from the stereo back to the sat-nav, for example, takes longer than necessary due to menu options sliding around trying to be fancy, and there were occasions when we missed a turning because of it.
The sat-nav inside the XKR-S is generally quite reliable, though. Its maps are stored on a DVD rather than solid-state media, so it's rather slow at times, but it allows full seven-digit postcode entry and has a useful split-screen mode that provides instructions for immediate turns alongside a bird's eye view of your overall route.
Our test XKR-S was fitted with the same optional 525W Bowers & Wilkins speaker system as the previous XKR. We're massive fans of this set-up, which provides Dolby Pro Logic II surround sound, alongside stereo and three-channel audio modes. Still, listening to it in this car, we couldn't help yearning for more, as it simply can't compete with the car's breathtaking exhaust note.
The number of media sources could also do with some improvement. The car lets you listen to DAB, AM and FM radio, has a six-CD in-dash changer, and offers iPod and USB connectivity, but it doesn't allow users to stream audio from devices via Bluetooth. As a result, anyone with a comprehensive cloud-based music collection, acquired using services such as Spotify, will have to play music via an auxiliary cable, which is a very inelegant solution.
The Jaguar XKR-S is a fantastic car, whose multifarious talents won't fail to astonish. It's savagely quick and remarkably agile around twisty roads and race circuits, yet it offers a level of comfort usually reserved for high-end luxury limousines.
Its cabin technology, while impressive on the whole, could do with sprucing up to bring it in line with Jaguar's new XJ, but don't let that put you off. The XKR-S is a wonderful piece of high-performance engineering that can easily trade blows with the Porsche 911 GT3 RS and Aston Martin V8 Vantage S.
Edited by Charles Kloet