The most dynamic, most agile, most visually dramatic production Jaguar ever built – the XK – made its world debut at the Frankfurt Motor Show in September 2006. Sculpted in lightweight aluminum, the 2007 XK accelerated faster, handled better, used less fuel and produced fewer emissions than its predecessor. It was the embodiment of Jaguar's promise of building only ‘Beautiful, Fast cars'.
In less than a year, Jaguar had taken the XK's performance to a new height with the introduction of the R-Performance version, the XKR. Powered by a supercharged 4.2-liter V8 delivering a muscular 420bhp, the R coupe can sprint from standstill to 60mph in a mere 4.9 seconds in coupe form, and go on to an electronically-limited top speed of 155mph.
Now, for 2008, just months after the debut of the XKR, Jaguar has taken its supercharged sportscar to a new level of luxury, refinement and technical advancement with the arrival of the limited edition XKR Portfolio. Rolling on 20-inch Cremona-style wheels and stopped by the largest, most powerful brakes a production Jaguar has ever carried, the XKR Portfolio adds real substance to its style. Just 255 examples will be offered in the ÚS.
'The XK is the first of a new generation of beautiful, fast Jaguars. It introduced a new design language to Jaguar that will be reflected in all our future models. It is the most technically advanced Jaguar ever, the most visually gorgeous, and the most fun to drive,'
says Marti Eulberg, executive vice-president Marketing and Sales, Jaguar North America.
'And as the XKR and now the XKR Portfolio have shown, it is a car that will continue to evolve, a Jaguar that will continue to have its claws sharpened,' adds Eulberg.2008 XKR PORTFOLIO IN DETAIL
• Únique exterior styling revisions include 20-inch polished Cremona five-spoke alloy wheels, polished aluminum side power vents and Celestial Black paint.
• Advanced aluminum construction, 420bhp supercharged 4.2-liter V8 engine and six-speed Jaguar sequential shift transmission with paddle shifters for superb dynamic performance.
• New high-performance Alcon braking system with 15.7-inch front rotors and 13.8-inch rears – the largest ever fitted to a production Jaguar.
• Choice of new interior veneer – sporty Engine-Spun Alloy – or elegant Satin American Walnut.
• First production Jaguar to use new Bowers & Wilkins speaker system exclusively crafted for XKR Premium Sound system.
For 2008, Jaguar is adding even more appeal to the ‘must have' XKR with its new, special edition Portfolio model. Just 255 XKR Portfolios will be offered in the Ú.S., each one featuring notable additions to the already extensive specification of the XKR, a car capable of accelerating to 60mph in just 4.9 seconds (5.0 seconds for the convertible) and hitting an electronically controlled top speed of 155mph.
The XKR's already powerful sporting styling cues – an aerodynamically-enhanced front bumper, bonnet louvres and aluminum-finish grilles and side power vents – will remain and exclusive Celestial Black exterior paint and 20-inch polished Cremona-style five-spoke alloy wheels add to the overall presence.
The XKR Portfolio will combine this acclaimed design and performance with Jaguar's engineering and craftsmanship skills to take the XKR to an even higher level. Every XKR benefits from its class-leading, advanced aluminum construction, which ensures that its power is matched by a dynamic, lightweight chassis that handles supremely, rides exceptionally well and stops with surefooted reassurance time after time.
Now, to offer even greater braking ability, Jaguar's Special Vehicles team has worked alongside leading brake manufacturer Alcon to create the largest, most powerful brakes a production Jaguar has ever carried. After extensive testing by experts at Jaguar's specialist engineering center, based next to the legendary Nürburgring race circuit in Germany, the new XKR Portfolio braking system was conceived.
Front brake discs measuring 15.7-inches in diameter – an increase of 1.8-inches over the standard XKR – are clamped by powerful six-piston calipers, while at the rear four-piston calipers operate on 13.8-inch discs. Innovative race-developed crescent-shaped grooves cut into the surface of the discs prevent a build-up of deposits on the brake pads and improve braking performance under extreme use.
By allowing the heat created within the system to dissipate quickly and efficiently, the XKR Portfolio's brakes produce fade-free performance whilst maintaining Jaguar's renowned blend of refinement and stopping power. Únique ‘R' branding on the front brake calipers reveals the six-piston set-up beneath.
Surrounding the XKR Portfolio's brakes are polished 20-inch five-spoke Cremona-style wheels, while behind the front wheels sit all-new power vents which are hewn from polished aluminum and incorporate the indicator side repeater and Jaguar signature ‘ingot'. An exclusive Celestial Black exterior paint will also serve to differentiate the XKR Portfolio edition.
A host of new additions to the interior further the luxurious look and feel of the XKR Portfolio. A unique, and quite beautiful, Engine-Spun aluminum veneer is standard on the Portfolio, while customers will also have the option of an elegant Satin American Walnut veneer. A new alloy and leather gearshift selector, soft-grab door handles, contrast stitching throughout the cabin, leather-edged mats with a Jaguar logo and distinctive Portfolio treadplates on the doorsills complete the effect.
The XKR Portfolio also marks another first for Jaguar: the first production example of its new partnership with renowned British audio entertainment specialists, Bowers & Wilkins. This world-leading loudspeaker manufacturer worked alongside Jaguar to create a stunning speaker system for the recent C-XF concept car, but the XKR Portfolio is the first production Jaguar to benefit from the relationship.
Taking Jaguar's 525-watt Premium Audio system with Dolby Pro Logic II surround sound as a starting point, Bowers & Wilkins have crafted a signature speaker system specifically for the XKR's cabin. High-output, low-distortion Kevlar mid-range speakers and specially designed aluminum-dome tweeters deliver superb mid-range and extended high-frequency responses. 2008 JAGÚAR XK IN DETAIL - KEY POINTS
• Coupe and Convertible each designed as a 2+2 sports car
• All-aluminum construction assists best-in-class torsional rigidity in coupe form. In convertible form, there is a 50 percent improvement in stiffness over the previous XK Convertible
• Aluminum construction ensures light weight, with Coupe and Convertible curb weight at 3,671 lbs (1,665 kg) and 3,759 lbs (1,705 kg) respectively
• In Convertible form, the Body-in-White weight is just 633 lbs (287 kg)
• Lightweight body offers a 10 percent improvement in power to weight ratio
• Intuitive controls and driver-focused technologies –Keyless Entry, Keyless Start and available Active Front Lighting – enhance driver enjoyment
• Spacious, elegant sports car cabin exemplifies Jaguar craftsmanship, luxury and quality
• Choice of naturally aspirated 4.2-liter Jaguar AJ-V8 engine, developing 300bhp, or supercharged 4.2-liter AJ-V8 with 420bhp
• AJ-V8 engine developed to satisfy ÚLEV II emissions requirements and features Exhaust Gas Recirculation
• Jaguar Sequential Shift 6-speed ZF automatic transmission system incorporates steering wheel-mounted paddles for manual gear changes
• XK Coupe reaches 60mph from standstill in 5.9 seconds and completes quarter mile sprint in 14.4 seconds XK Convertible takes just 6.0 seconds to reach 60mph
• Supercharged XKR Coupe accelerates from 0-to-60mph in just 4.9 seconds – Convertible in 5.0 seconds
• Electronically limited top speed of 155mph (250 km/h)
• Convertible roof operates electrically in less than 18 seconds to be stowed below lightweight aluminum tonneau cover DESIGN
The all-new XK is visibly more assertive and sportier than the model it replaces, but in true Jaguar tradition it is also elegant, understated and mature. In hard-top guise it has classic, ground-hugging coupe proportions, with long hood, steeply raked windshield and rear window, arch-filling wheels, and minimal overhangs. The front-wing power vents are a new Jaguar styling signature recently seen on the special edition XJ Super V8 Portfolio; the distinctive oval grille opening, prominent hood power-bulge and practicality-enhancing rear Liftback all echo the classic E-type, while details like the sweeping front and rear light shapes and powerful stance catapult Jaguar sports car design firmly into the 21st century.
Inside the new XK, traditional craftsmanship and contemporary luxury materials, like finely stitched leather, contrast with a choice of more high-tech trim surfaces including metallic finishes. The layout is driver-focused and sporty, with excellent ergonomics and body-hugging seats, set low against the high waistline to give a strong ‘cockpit' feel. With the new XK's longer wheelbase, wider tracks and taller roofline, the 2+2 layout has significantly more interior space for front seat occupants than the XK that it replaces.
Available in both two-door Coupe and Convertible forms, each model was developed in parallel under one umbrella program. The decision to give the Convertible version a classic soft-top rather than a folding hard-top means the open option offers exactly the same 2+2 seating layout, without compromising the elegant lines of the rear body, the strong, rising waistline or the light weight of the car.
The fully-lined triple-layer roof has exceptional wind and road noise isolation. It opens and closes at the touch of a button in less than 18 seconds, and when dropped it stows neatly below a rigid aluminum tonneau cover without unacceptable intrusion into the luggage space. Furthermore, the loadspace can be increased by approximately 3 cu. ft. (83 liters) by stowing the retractable loadspace separator when the Convertible roof is up. The use of a soft-top has also allowed the exterior body to be designed with much cleaner lines and a relatively low deck, meaning the door waist line can be carried right through the vehicle from the front of the car to the tail.
The roof is constructed from three layers, which also insulate against wind and road noise. The outer layer is a completely waterproof cloth/rubber/cloth laminate, and the inner layer is a luxurious cloth lining which is taut and smooth when the roof is closed.
The ‘sandwich filling' is an insulation layer, using 3M Thinsulate™ material. This gives significantly better insulation for less than half the thickness of the previous XK soft-top construction. It is not only lighter, it takes up significantly less volume when the roof is stowed, allowing more space for passengers and luggage.
The rear window is made of toughened glass, with a heating element, and is bonded into the roof. The door glass automatically drops slightly as the doors are closed, and rises again to seal inside the roof water channels. Additionally, the Convertible's rear windows can be lowered even when the roof is up.
The soft-top is raised and lowered by a single press of a button, using hydraulic actuators and electronic controls. It will go from fully open to closed in under 18 seconds, which includes automatically raising the side windows and rear quarter glasses at the end of the cycle.
When the soft-top is up, the profile has sleek, elegant lines and the ‘C' pillar area visually fits comfortably over the rear wheels. Attention to detail is continued with a chrome finishing strip fitted to the door capping and continuing around the soft-top base.
The new XK was created by Jaguar's new design team under the leadership of Design Director Ian Callum, to push Jaguar deeper into the 21st century. The new XK's lines are bold and beautiful, powerful but elegant. In Ian Callum's words, it looks 'just like a Jaguar should – powerful and exciting. That power comes from a sense of tension, muscle and form and is very much part of the new design language we are creating.'
Although the new XK looks very compact, it has excellent luggage space. Even with the rear overhang being a full 4.8 inches shorter than the previous XK, the rear luggage volume is only 0.28 cu. ft. less, or 0.78 cu. ft. more when the optional run flat tires are specified – and of course it has gained the enormous benefit of the all-new Liftback design, which provides excellent access to the loadspace area.
'I am very proud of the new XK,' says Ian Callum. 'It is contemporary with wonderful modern proportions yet we have succeeded in integrating design cues from our heritage. The front grille, for example, is pure E-type, and makes the perfect statement that this is, first and foremost, a Jaguar.' LIGHTWEIGHT VEHICLE TECHNOLOGY
Key to the all-new XK's character is Jaguar's industry-leading bonded and riveted aluminum monocoque body structure, introduced with the latest XJ saloons. The aluminum body incorporates the latest thinking in epoxy bonding and riveting techniques to produce a chassis that is very safe, as well as very light. In fact the new XK's aluminum chassis is significantly lighter and stiffer in both Coupe and Convertible form than the steel model it replaces – over 30 percent stiffer and an impressive 50 percent stiffer respectively.
As a consequence the new XK accelerates faster, uses less fuel and produces lower emissions than the model it replaces, while offering high levels of safety, reduced noise and vibration intrusion, and improved ride and handling characteristics thanks to improved suspension dynamics.
Jaguar's Lightweight Vehicle Technology is unique in the industry as a complete aluminum monocoque body structure as distinct from an aluminum spaceframe with separate aluminum panels. Developed from aircraft industry methods, where strength is critical for huge temperature variations and very high stresses during take-offs and landings, Jaguar's manufacturing process produces a massively strong but very light structure. The new XK takes the concept a step further with extended use of lightweight aluminum castings and extrusions as well as the pressed aluminum panels. Its strength and light weight come from the way the shell is constructed, using new jointing technologies developed by Jaguar and its suppliers.
There is only a single welded joint in the new XK Coupe body, the one ‘cosmetic' joint on the roof. That also has an environmental benefit in that the body construction needs no high electrical current, produces no welding sparks or fumes, and needs no water for cooling.
All the other joints in the new XK shell are formed using Jaguar's unique combination of riveting and bonding. Most joints are produced using self-piercing rivets applied by hydraulic pressure against a fixed tool. Where access to only one side of the joint is possible, as in some of the new extruded box sections, a new riveting process has been developed; and where particularly high stiffness is required in a joint, a combination of riveting and bonding is used – with the adhesive bond in effect creating a continuous joint which is stronger than a similar, riveted-only joint.
All visible exterior panels are bonded to the underlying structure, and a new automated seam-sealing process seals all relevant areas of the shell before painting, to ensure that no gaps are missed.
In the new XK, a secondary front bulkhead of aluminum and composite materials helps reduce transmission of noise from the engine compartment and provides a dry area under the hood for accommodating electrical components. The new structure also has benefits in refinement; castings are used for the mounting points for the engine, transmission and suspension make those points significantly stiffer, further reducing transmitted noise and helping to improve suspension dynamics. In terms of long-term strength, Jaguar's all-aluminum shell has durability approaching twice that of a traditional spot-welded steel body.
Another major advantage of this Lightweight Vehicle Technology is that all the necessary stiffness is in the structure of the bodyshell, with very large rectangular-section side sills. So the Convertible, even without a roof, does not need the traditional extra stiffening panels seen on many other convertibles – meaning there is no added weight and no penalty in stiffness or refinement. The aluminum monocoque construction is the biggest contributor to the low overall vehicle weight of the new XK, and the Coupe shell is over 30 percent stiffer than the previous model, while the Convertible boasts an impressive 50 percent improvement in torsional rigidity.
That lightweight body significantly also offers a 10 percent improvement in power to weight ratio. The all-new XK is up to 90 percent stiffer than key rivals, with a curb weight of just 3,671 lbs (1,665 kg). In Convertible form the BIW weight, at just 633 lbs (287 kg) is 19 percent lighter than the previous XK Convertible.
'The lightweight vehicle architecture really helps the XK to handle, steer and brake better than ever,' says Al Kammerer, Product Development Director, Jaguar and Land Rover. 'Imagine how much easier it is to turn a lightweight object traveling at speed compared to a heavy one. The aluminum chassis makes the XK so much more controllable in corners and a whole lot of fun to drive!'
Safety is another major benefit of this very strong construction method. That is partly inherent in aluminum as a material, which absorbs significantly more energy per pound of material weight than steel when it is deformed. But the strength advantage doesn't only apply to high-speed impacts, it also means lower-speed accident repair costs are kept to a minimum. The reduction in the number of joints in the all-new XK further increases strength, and the front of the body is protected by easily replaced ‘crush cans' that absorb the energy in impacts up to just over 9mph (15 km/h).
The all-new XK's all-aluminum doors are each over 13 lbs (6 kg) lighter than an equivalent steel door and their mountings are significantly stiffer, which allows smaller gaps. Mounting the window glass rails directly to the aluminum castings at the front and rear of the door gives better sealing from the frameless layout, and an impressively solid sound and feel when closed.
The all-aluminum Liftback rear door is strong, light and simple to operate. Once it has been lifted manually through the first 20 percent of its opening arc, gas struts lift it the rest of the way.
With lower weight and higher strength, Lightweight Vehicle Technology is the starting point for improved performance, safety, refinement, economy, emissions performance and driving dynamics in the new XK. ENGINES – THE POWER TO PEFORM
The 2008 XK Coupe and Convertible come with a choice of two powerful four-cam versions of Jaguar's acclaimed 4.2-liter AJ-V8 – the 300bhp naturally-aspirated version and a supercharged version for the XKR and XKR Portfolio that delivers an impressive 420bhp.4.2-liter normally-aspirated AJ-V8
A wide spread of torque is an important ingredient in the XK's effortlessly sporty character. The naturally-aspirated V8, with 303 lb-ft of torque at 4,100rpm, delivers more than 85 percent of torque all the way from 2,000 to 6,000rpm. Yet it still offers fine fuel economy and low emissions figures, satisfying stringent ÚS ÚLEV II emissions regulations.
And it has the power to perform. Accelerating from standstill-to-60mph takes just 5.9 seconds (0-100km/h in 6.2 secs) and it will continue to rush to an electronically limited maximum speed of 155mph (250 km/h). It also delivers instant throttle response and broad flexibility for punchy performance across the range. With the new XK's weight savings, the new naturally aspirated 4.2's standing quarter-mile time of 14.4 seconds is less than half a second off the pace of the previous supercharged 4.2 XKR.
The compact AJ-V8 engine has very stiff but lightweight all-aluminum construction, with eight cylinders in a 90-degree ‘V'. The combination of strength and lightness begins with a ribbed cylinder block and cylinder heads. The 4.2-liter version has bore and stroke of 3.39 x 3.56 inches for a capacity of 4196cc. The fully balanced four-throw, six-counterweight crankshaft is supported in five main bearings. The connecting rods use split-fractured big-end journals for strength with light weight and perfect balance.
Each cylinder head carries two chain-driven overhead camshafts, which are hollow, to save weight and improve performance by allowing higher engine speeds. The camshafts operate four valves (two inlet and two exhaust) in each pentroof combustion chamber, around a central spark plug. An unusually narrow 28 degree included valve angle allows a compact combustion chamber shape and narrower heads, which benefits overall packaging.
The inlet camshafts allow variable inlet valve timing, with VCP Variable Camshaft Phasing, which is controlled by three-dimensional digital maps stored in the Engine Management System, on the basis of engine speed, throttle position and oil temperature data gathered from a series of sensors in the engine. The phase of the inlet camshafts is varied hydraulically and continuously (advancing the opening of the inlet valves at high engine speeds to allow the combustion process to start earlier). That delivers faster throttle response at all engine speeds, and gives optimum performance at all speeds and under all loads - with more torque at low speeds and maximum power at high speeds, while optimizing fuel consumption.
The major difference between this engine and the previous generation 4.2-liter XK engine is in the fuel injection technology. This latest V8 uses multi-hole injectors, which improve the fuel spray pattern in the combustion chambers, improving both power and fuel efficiency.
Optimum throttle response (a crucial ingredient in confirming the new XK's sports car character) is delivered by full ‘drive-by-wire' electronic throttle control, with no mechanical connection between the accelerator pedal and the throttle body.
Equally important for its new role in Jaguar's sportiest cars, the 4.2-liter engine has been engineered to give the sound expected from a real sports car engine – especially under acceleration – but without being undesirably noisy. The new XK's Semi-Active Exhaust system varies the flow of exhaust gases through the main, large silencer box depending on the pressure in the system, and features acoustically tuned tailpipes that eliminate low speed boom.
There is also an underfloor resonator with two chambers (one for each cylinder bank) which balances the sound from the two banks. By tuning the sounds from the air-induction system and the exhaust system, Jaguar concentrated on both the solid, powerful low-frequency sounds and more technically ‘sophisticated' higher frequency sounds, to give a feeling of power and performance.4.2-liter Supercharged AJ-V8
The ability to call upon impressive reserves of power and acceleration in an instant is the hallmark of every great Jaguar. The new XKR and XKR Portfolio ensure this by using a remarkable 4.2-liter supercharged AJ-V8 engine. Producing 420bhp ( SAE) at 6,250rpm and 413 lb-ft of torque at 4,000rpm, it is capable of propelling the Coupe version to 60mph in 4.9 seconds (5.0 seconds for the Convertible) and onto an electronically limited top speed of 155mph (250 km/h).
The addition of a supercharger and twin air intakes means the new XKR benefits from a 120bhp ( SAE) power increase over the normally aspirated 4.2-liter XK with which it shares its engine configuration. Torque, so essential for instant acceleration at any engine speed, also increases significantly – by 36% over the XK, although the overall weight of the XKR is raised by just 154lb (70kg). Consequently the power-to-weight ratio compared to the normally aspirated 4.2-liter XK is an impressive 34% higher.
And in comparison to the previous generation XKR, the new engine produces more power and more torque. Combined with the significantly stiffer and lighter aluminum monocoque body structure of the new XKR, these performance improvements lead to a significant leap in the power-to-weight ratio of 12% over the previous XKR and an equally useful jump of 7.7% in the torque-to-weight ratio. To achieve the equivalent improvements in power and torque-to-weight in the outgoing XKR would have required nearly 50 more horsepower. Consequently, the 0-60mph sprint time of the new XKR Coupe is reduced by 0.3 seconds.
The heart of these significant performance improvements is the XKR's lightweight eight-cylinder engine with an Eaton supercharger. The water-cooled cylinders are arranged in a 90-degree V configuration and the crankshaft is supported by five main bearings. Each of the two cylinder head assemblies incorporates twin camshafts operating four valves per cylinder. One of the reasons for the engine's impressive output is the continuously variable valve timing which helps to deliver a wide spread of torque. The engine uses an Electronic Return-less Fuel System (ERFS) and a three-way catalyst exhaust system.
The increase in power and torque over the outgoing XKR model is down to two significant additions to the engine. The air intake supply to the engine has been significantly enhanced thanks to the use of twin air inlets, and a Variable Inlet Camshaft Timing system is used for the first time on the XKR. By continuously adjusting the timing of the inlet camshaft on both banks of the V8, depending on the engine speed and load, Jaguar's engineers have ensured large improvements in torque, particularly at lower revs.
The system is controlled by the Engine Management System ( EMS) which receives engine speed, throttle position and oil temperature data from its sensors. The EMS determines the correct inlet camshaft timing by continuously referring to a digital three-dimensional map developed to provide optimum performance. The EMS then transmits the appropriate signals to two solenoids that control the degree of hydraulic force provided to the valve actuators.
The normally aspirated 4.2-liter XK has been praised for its acoustic qualities, remaining unobtrusive and relaxed at modest speeds but producing an unmistakable V8 soundtrack when worked hard. On the XKR, the noise from the supercharger threatened to dominate the acoustic character and mask the underlying sound quality. However, through enhancements to the vehicle acoustic pack, the supercharger noise has been reduced by 5dB compared to the previous XKR.
This approach to acoustics allowed the engineers to concentrate on using the exhaust system to deliver the best possible sound quality character. This was accomplished through the use of the XKR's Active Exhaust system which varies the flow of exhaust gases through the main silencer box to ensure that the XKR remains quiet at cruising speeds, but delivers a substantially more purposeful sound quality character under hard acceleration.TRANSMISSION
Engine : 4.2 L., 8-cylinder
Power: 300 hp
Torque: 310 ft-lbs
The XK uses the latest version of Jaguar's class-leading six-speed epicyclic automatic transmission, which is widely regarded as one of the best automatic transmissions in the premium, sports car market. It features Bosch Mechatronic shift – an electro-hydraulic shift mechanism whose adaptive shift strategy responds to both road conditions and driving style, to give the smoothest shifts with optimum performance.
The XK's transmission introduces a new generation of automatic gearshift for Jaguar, replacing the familiar ‘J' gate with the Jaguar Sequential Shift system with Park, Reverse, Neutral, Drive and Sport modes. The fully automatic Drive mode adapts to individual driving styles, while a Sport Auto mode can also be selected. This offers an even more responsive fully automatic shift strategy.
For the first time in a Jaguar, drivers can use steering wheel-mounted paddles to change gears. In either Drive or Sport modes instant access to manual operation is achieved via the shift paddles. In manual mode, the transmission controller uses an alternative parameter set to control gear shifts, enabling delivery of extremely rapid and responsive manual shifts, whilst maintaining class-leading Jaguar shift quality in automatic modes. Interaction with the torque-based engine management system allows for precise torque control during shifts – engine inertia is used to enhance acceleration during upshifts, and an engine torque increase (‘throttle blip') is used to significantly shorten over-run downshifts.
The epicyclic geartrain utilizes clutch-to-clutch synchronous shifting to ensure that a controlled amount of torque is always being transferred during power on upshifts. This makes the shift much smoother than in the automated manual gearboxes adopted by some of the new XK's competitors, where the use of an automated clutch completely interrupts the flow of torque during shifts.
The extremely rapid shift times often quoted for automated manual transmissions relate solely to the duration of this torque interrupt. The true shift time is significantly longer, since the clutch must be disengaged prior to the ratio change, and re-engaged after. In contrast, the Jaguar Sequential Shift suffers no torque interrupt resulting in a smoother more powerful shift feel, and a very short total shift time of approximately 600 milliseconds from the driver touching the shift paddle to the completion of the shift event.
In fact, during development, comparison tests between Jaguar Sequential Shift and rival automatic transmissions in the class showed the new XK's transmission to be the fastest system of all, changing gear at least 400 milliseconds faster than a standard automatic and 100 milliseconds faster than the best automated manual system. CHASSIS AND DRIVING DYNAMICS
The light, ultra-stiff all-aluminum monocoque body of the all-new XK forms a solid basis for the suspension components. The reduced body weight also allows other components to be located as required to deliver optimum weight distribution and avoid any compromises with optimum suspension layout.
The XK uses Jaguar's well proven and classically sporty combination of unequal length wishbones at the front and unequal length wishbones using the driveshafts as upper links at the rear. The body's light weight and careful packaging provide the perfect platform for Jaguar's renowned expertise in combining exceptional handling and roadholding with comfort and refinement.
In unison with this ultra-stiff body Jaguar is able to use a conventional, mechanically sprung suspension layout, with coil springs and telescopic dampers all round, that gives more natural, more positive feedback to the driver, exactly as a sports car should.
That technology includes a new version of Jaguar's Computer Active Technology Suspension ( CATS), which is a two-stage adaptive damping system that ensures the optimum balance between ride and handling whatever the road conditions or style of driving. The car's pitch and yaw rates are measured using accelerometer sensors. That data, plus information on steering wheel angle and brake demand, is processed by the control module, and electronically controlled hydraulic valves continuously vary the damper settings accordingly.
In the previous XK, the CATS system adjusted front and rear dampers in pairs, limiting the control variation to pitch only. The all-new XK's version controls all four dampers separately, which allows control of roll as well as pitch, for even better ride and handling balance, with a very sporty feel. XKR – FIRMING ÚP
To ensure optimum ride and handling, the XKR's springs and dampers are uprated compared to the normally aspirated XK. The front spring rate is increased by 38% and the rear spring rate by 24%. Allied to the Servotronic steering system, which has also been tuned both mechanically and electronically to give the steering more weight and even greater response, the suspension ensures confidence-inspiring handling without any loss in refinement and comfort levels.
Because of the inherent strength and stiffness of the chassis, the only significant addition to the XKR's structure is an additional rear suspension brace mounted between the rear damper towers to accommodate the significant increase in rear spring rate. This also allows the Convertible to utilize the same dynamic settings as the Coupe model. WHEELS & TIRES
The 4.2-liter XK has 18-inch Venus-style alloy wheels as standard, with the option of 19-inch Carelia-style alloy wheels or 19-inch chromed Sabre-style wheels. On each model, and whatever the wheel diameter, the rear wheels are wider than the front ones – to optimize the steering characteristics, handling balance and traction.
With 19-inch wheels, run-flat tires will be available as optional equipment. They are designed to allow the driver to drive on following a puncture, and are capable of traveling for 50 miles (81 km) at speeds of up to 50mph (81 km/h) after a total deflation.
For the supercharged XKR, a 19-inch Jupiter-style wheel comes standard, while the new-for-2008 XKR Portfolio comes equipped with polished 20-inch Cremona-style alloys.
The new XK offers Jaguar's new Tire Pressure Monitoring System (TPMS), which uses a pressure sensor in each wheel continuously to monitor each tire. Data from the sensor is transmitted by radio frequency to a receiver in each wheel arch, and in turn to the central control module.
In the event of a loss of pressure, the system displays clear warnings in the instrument cluster to help the driver to take appropriate action. The TPMS system is standard equipment. Where run-flat tires are fitted, no spare wheel needs to be carried in the luggage compartment and the unused spare wheel well is fully trimmed and shaped to take a suitcase and increases the total loadspace by 1.06 cu. ft. (30 liters).
In addition to the TPMS system, the XKR Portfolio also comes standard with Jaguar's new Instant Mobility System, which replaces the traditional spare tire with a flat tire repair kit. The kit includes a latex mixture to seal the tire and an inflater pump to restore tire pressure. The elimination of a spare tire also provides additional storage space within the car's trunk.BRAKES
The new XK features a braking system with bigger ventilated discs, more stopping power, better pedal feel and better resistance to fade than the previous XK. Extensively tested at facilities including Nardo in Italy and the Nürburgring test track in Germany, where Jaguar has a permanent research facility, the brakes are also specifically tuned to be more responsive for the enthusiastic driver.
The new XK has four-channel ABS with analogue control which is more refined than simpler ‘on-off' digital controls, and Electronic Brakeforce Distribution which ensures the correct balance of braking forces between all four wheels irrespective of road or vehicle-load conditions. It also uses Jaguar's excellent Electronic Parking Brake system.
Larger ventilated brake discs at the front ensure higher braking performance for the XKR. The front brake disc diameter has increased from 12.8in to 14.0in (326mm to 355mm), and the thickness from 1.2in to 1.3in (30mm to 32mm), which not only improves the braking performance but also the system's resistance to fade. The braking system also includes four-channel ABS, Electronic Brake Force Distribution, Hydraulic Brake Assist to increase brake pressure during an emergency stop, and Jaguar's Electronic Park Brake function.
For the XKR Portfolio, Jaguar worked with leading brake manufacturer Alcon to create the largest, most powerful brakes a production Jaguar has ever carried. With front brake rotors measuring 15.7 inches in diameter – an increase of 1.8-inches over the standard XKR – are clamped by powerful six-piston calipers, while at the rear four-piston calipers operate on 13.8-inch discs. Innovative race-developed crescent-shaped grooves cut into the surface of the discs prevent a build-up of deposits on the brake pads and improve braking performance under extreme use. DYNAMIC DRIVING AIDS
The new XK offers the most up-to-date electronic dynamic safety systems, including Traction Control System (TCS) and Trac DSC function.
TCS assists traction from rest or on slippery surfaces by applying the appropriate brake to a driven wheel if slip is detected, transferring drive torque to the other driven wheel where that has more grip. DSC uses selective braking and controls engine torque output to prevent excessive oversteer or understeer, excessive or fast transient roll, and unwanted wheel lock under hard engine braking.
Trac DSC is a feature aimed at the sportier and more experienced driver. It is a driver-selectable second stage of the DSC stability control that retains the full TCS traction control function (and ABS and EBD functions) but raises some of the sideways slip thresholds by delaying the intervention of the DSC functions. That allows the skilled driver to take more responsibility for controlling the car's cornering attitude. It is not possible to select the function unintentionally – the driver has to hold the switch for three seconds or more to select this level of DSC.
To confirm the all-new XK's driving character, steering feel was a key issue. The new XK features Jaguar's Bosch Servotronic 2 steering, as used on the XJ but re-engineered to suit a high-performance sports car. It is a mechanically assisted system (hydraulically powered by an engine-driven pump) with electronic control. The control module uses data about vehicle speed and steering input to regulate the degree of steering assistance. It provides higher assistance at low speeds for easy maneuvering, and less assistance at higher speeds for increased feedback to the driver – resulting in class leading steering characteristics. OTHER DRIVER AIDS
Jaguar believes in the intelligent use of technology - to enhance the driving experience, while avoiding over-use of technology that only adds complexity rather than user-benefit. But Jaguar also believes in making its cars more intuitive and relaxing to drive. The new XK offers a range of driver aids that support that philosophy, including Cruise Control or Adaptive Cruise Control, Forward Alert, parking sensors, and automatic lights and wipers.
Cruise Control is standard on the new XK and allows the driver to set a fixed speed via steering wheel mounted controls, with the usual accelerate, coast and resume functions. Adaptive Cruise Control is an option, and in addition to the normal cruise control functions it uses microwave radar technology to monitor the road ahead and automatically reduce speed if traffic conditions make it necessary. It normally reduces speed simply by reducing power, but if necessary (for instance if another car pulls sharply into your path on a motorway) it will also use the ABS braking system to slow more quickly, as appropriate. The gap to the vehicle in front is based on time, so as speeds increase, so does the gap. It is also possible to adjust the gap to three levels by a simple steering wheel switch, to a space that the driver feels most comfortable with.
Contained within the ACC is Forward Alert, which uses the XK's forward-facing sensors to help warn the driver of a potential collision. When approaching another vehicle or other obstacle it continuously estimates the braking effort required to avoid it. If the distance available falls below the safe threshold, Forward Alert sounds an audible warning to prompt the driver to take appropriate action. It is still the driver's responsibility, though, to stop in an emergency.
Rear parking aids are standard on all-new XK, with four ultrasonic sensors in the rear bumper which can detect objects up to 1.9 yards (1.8 meters) away to the rear and corners of the car and give an audible warning. The warning comes through the car's audio system and changes tone with the proximity of the car to the object. The car's touch screen gives a visual indication of which part of the car is near the object.
The all-new XK's wiper system is rain sensitive and its headlights are light sensitive, so when either function is switched to automatic mode it will respond to rain or darkness respectively – although it is also possible, of course, to control wipers, washers and lights manually.
The standard bi-xenon headlamps incorporate power-wash and self-leveling systems. A separate beam comes on at low speeds and when the direction indicator is used, to light up an area to the sides of the car for low speed handling. The optional Active Front Lighting system provides enhanced night-time visibility by automatically swiveling the dipped beam lenses depending on road speed and steering angle.
At the rear, the lamps are split between the body and the rear liftback or trunklid. The liftback segments incorporate a single reversing light on one side and a high intensity fog light on the other. Both use high-power LED lights, and the new XK's white LED reversing light is an industry first. INTERIOR
The interior of the new XK is as modern and forward-looking as the exterior, and designed specifically with the sporty, enthusiast driver in mind. It is roomy and comfortable, and in its choice of materials and equipment, it is genuinely a premium, luxury car. It was important that it displayed the understated craftsmanship and restrained contemporary luxury associated with Jaguar.
But being a sports car there was no place for overly ornate or fussy design – ergonomics were more important. So the seats hold the driver and passengers firmly but comfortably, the interior has a light and airy ‘cockpit' feel, and the lowered position of the instrument panel also gives a feeling of greater cabin space.
That sense of well-being comes in part from the fact that the car is extremely roomy, and has the classic 2+2 sports car layout with individual sculpted seats in the rear. Compared to the previous generation XK, there is 2.32in more seat-track travel, 2.13in more front leg room, 0.8in more front head room and 1.4in more shoulder room. There is also better foot space all round, and Jaguar's electronic parking brake liberates the space that was previously needed for the outboard handbrake lever. There are more interior stowage spaces, and the combination of more interior space plus longer seat travel makes rear seat access through the long doors easier.
The main instrument binnacle in front of the driver is designed to relate to the shape of the three-spoke steering wheel and it houses two classic round dials flanking a 256-color Driver Information Center based on Thin Film Transistor technology. The speedometer and tachometer dials are backlit with green backgrounds and their pointers are illuminated with white light.
The large, seven-inch center console touch-screen is a menu-driven information and control system. It is designed to offer the required number of functions, but with minimum distraction and complexity to the driver – so in each menu level a maximum of only five items is available for selection. For example, the first menu level allows the driver to select between climate, audio, navigation, telephone and vehicle settings. To make selection easier for some modes and to avoid distraction from the road, when the driver's finger is close to but not touching one of the screen icons, that particular icon ‘grows' and an audible indication of the selection is given, so the driver can touch the correct icon without even having to see it. Very importantly for safe and positive operation, there are ‘home' and ‘back' buttons, and two manual buttons below the screen for ‘home' and ‘off' functions at a single touch.
Where available, the center screen also incorporates the display for the standard DVD-based satellite navigation system, which is also controlled via the touch screen. A significant advance over previous systems is that as well as giving turn direction instructions, the new XK's system also gives audible ‘towards' information at junctions – to the main town or city indicated by the local signpost, or (on a local level) to the next street name. Full zip code-based information is a further enhancement from previous systems.
As well as being a sports car, the new XK is a premium luxury car, and is equipped as such. Its sophisticated dual-zone climate control system (which can be regulated via the touch screen as well as by its conventional controls) has a comprehensive list of features including heating and cooling, humidity control which senses the risk of misting and switches to a dehumidified airflow to the windshield area, and automatic demisting after cold starts. The defrost function includes heated front and rear screens and heated mirrors. Heated seats (there's even an optional heated leather steering wheel) are controlled by the climate control system, and selectable from the central touch screen.
In the Convertible, a dedicated strategy operates when the car is being driven with the roof down, automatically changing the distribution of the airflow (warm or cool) to give more flow to the face vents.
The new XK offers a choice between high- and optional premium-quality audio systems. The standard six-speaker high-spec system supports conventional audio CDs as well as discs containing MP3 digital files, and the single dash-mounted CD slot is actually a six-disc changer. The premium system, by Alpine, has eight speakers, a remote six-channel amplifier, 520 watt output and Dolby Pro Logic II Surround Sound.
The built-in communication interface is Bluetooth-based, and can communicate wirelessly with compatible Bluetooth mobile phones – which only have to be in the passenger compartment, for instance in a brief case or jacket pocket. The completely hands-free system has volume and answer controls on the steering wheel, and a ‘do not disturb' mode to inhibit incoming calls when selected. The dialing keypad is contained in the touch screen and can be selected from the telephone menu; and the touch-screen can also display phone book and incoming call information.
The interior combines traditional luxury and high technology. The choice of materials was as important as the shapes, so it is important that they are seen – and details like the traditional stitching are an integral element of the design. There is a choice of two leather trims including Soft Grain, which can be extended as an option to cover the instrument panel top, door cappings and seats.
There are two veneer options – Burl Walnut, and the much lighter, more modern Poplar wood. Where traditional wood veneers are specified, they are produced by Jaguar's own highly specialized, in-house wood veneer department.
For 2008, interior craftsmanship is elevated even further with the use of a new, richer headliner material called Morzine (in the XKR it's a suede-like material called Alston).
The XKR benefits from a unique sports seat design with additional lateral support for both the driver and front seat passenger. To distinguish the interior, an ‘R' badge is featured on the headrests, tachometer, steering wheel and gear selector. The design of the standard aluminum interior veneer is also unique to the XKR, featuring a unique ‘weave' pattern. For 2008, it also features polished stainless steel pedals.SAFETY
The 2008 XK is engineered to meet all worldwide impact requirements with only one design, and its effectiveness was proved using many computer-simulated and real world crash tests. Enhanced safety features play a major role, both for passenger and pedestrian protection and the new XK uses a passive bumper system, the design of which helps to mitigate pedestrian leg injury through the use of crushable foam and plastic covering.
The new XK has comprehensive protection for driver and passengers, starting with the inherent strength of its all-aluminum body construction and effective energy absorbing deformation zones. It offers a driver airbag which senses seating position, whether the driver is wearing a safety belt and the severity of any impact, and deploys the airbag accordingly. It has a passenger front airbag that helps minimize injury even if the passenger is sitting awkwardly or too close to the airbag, and there are two combined front-seat head and thorax side airbags developed to help protect occupants in the event of impacts with larger vehicles and stationary objects such as poles.
The XK is also fitted with Jaguar's Protec® dynamic head restraint system, which is designed to minimize whiplash injuries in the event of an impact from behind, by automatically pushing the head restraint forward to support the head and reduce the risk of injuries to the neck. It also has LATCH child-seat fixings in both rear seats, plus a top tether that gives additional security in fixing LATCH-compatible child seats.
Although they are not a legal requirement, the Convertible features a Roll-over Protection Device consisting of two aluminum hoops that are automatically deployed if the car's sensors detect the onset of a roll-over accident. That creates a protected area between the hoops and the reinforced windscreen structure around the restrained occupants. The system is deployed by an advanced solid-state gyro sensor system. It also has a patented design to allow it to deploy through the rear window area if the roof is up, so the lines of the car have not been compromised by the inclusion of this safety system. SECÚRITY
The new XK features two-stage unlocking, which unlocks the driver's door with one push of the unlock button and the passenger door with a second push.
Amongst the user-friendly advanced technologies in the all-new XK is the Jaguar Smart Key System, which provides Keyless Start with a push-button starter, and keyless entry simply by carrying the Jaguar Smart Key in your pocket or bag.Source - Jaguar