"Our engineering team worked to the brief of creating a car that is 120% and more of an XK - the ultimate sports GT for the real world. We wanted the performance and dynamism you would expect of an XKR but were careful to retain that exceptional blend of sporting luxury that every Jaguar must have and which was so convincingly demonstrated with the XK. The bottom line is: if you like the XK, you'll absolutely love the new XKR."

The result of that engineering brief is a car that performs in any condition, at any speed. With superb torque at low engine speeds, instant acceleration is always available should you demand it. Similarly, the advanced steering and suspension set-up means the new Jaguar XKR switches effortlessly from relaxed grand tourer to honed sports car with ease. It is everything the XK is and much more.


Supercharged 4.2-liter engine

The ability to call upon impressive reserves of power and acceleration in an instant is the hallmark of every great Jaguar. The new XKR ensures this by using a remarkable 4.2-liter supercharged AJ-V8 engine. Producing 420bhp (SAE) at 6,250rpm and 413 lb-ft (560Nm) (EEC) 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 (250kph).

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 Jaguar XKR, these performance improvements lead to a significant leap in the power-to-weight ratio of 12% over the previous Jaguar 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 Jaguar 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 Jaguar 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 Jaguar 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 Jaguar 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.

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