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Powertrain - (Global)

August 28th, 2007





The new XF will be available with a choice of four engines - 2.7-litre V6 turbodiesel, 3.0-litre V6 petrol, 4.2-litre naturally aspirated V8 petrol, and 4.2-litre supercharged V8 petrol. All will have that classic blend of power and refinement that makes Jaguar stand out from its rivals, says Mick Mohan, XF Chief Programme Engineer:

"The XF's engines combine effortless performance, unrivalled character and an impeccable pedigree. The six-speed automatic transmission is the best Jaguar has ever had. The Jaguar Sequential Shift™ manual gearchange adds a whole new level of functionality. This combination - already proven in the XK- produces excellent powertrains for a very sporting Jaguar."

Both petrol V6 and diesel V6 engines are offered in the Luxury models; the naturally aspirated V8 will be Premium Luxury only and the supercharged SV8 has its own unique specification, for a very logical, easily understood range.

The Euro IV compliant twin-turbocharged 2.7-litre 24-valve V6 diesel delivers high efficiency, high performance and class-leading refinement - its headline figures including 152kW (DIN) and 435Nm of torque. With its Compacted Graphite Iron (CGI) cylinder block and aluminium cylinder heads it is the lightest diesel engine of its type and size - making a significant contribution to the new XF's power-to-weight ratio, performance and fuel economy.

The V6 diesel features the latest generation high-pressure Common Rail direct-injection, 'multiple pilot' injection, and piezo-electric injection control, allowing sophisticated management of the injection patterns to make combustion smoother and quieter. Four valves per cylinder and advanced combustion chamber shapes contribute to high combustion efficiency with low combustion noise, alongside very low mechanical noise levels.

Emissions are further reduced by using twin variable-geometry turbochargers with electronic control, exhaust gas recirculation, and a variable-swirl intake system. Using two small turbochargers, with 'drive-by-wire' throttle control, rather than one larger unit, also gives a quicker, smoother response.

The 3.0 litre V6 petrol engine is another compact, lightweight, all-aluminium design with four overhead camshafts, four valves per cylinder, VCP Continuously Variable Cam Phasing and variable geometry air intakes. It produces 175kW (DIN) and 293Nm peak torque - with more than 80 percent of peak torque from below 1500rpm to maximum engine speed at 6800rpm.

Variable Camshaft Phasing produces faster response and performance at all engine speeds - with more torque at low speeds and maximum power at high speeds. It also provides internal exhaust gas recirculation, reducing both hydrocarbon and NOx emissions.

The 4.2 litre V8 comes in naturally aspirated or supercharged versions. With a ribbed aluminium block and cylinder heads it is very light but extremely strong, and its superb structural stiffness minimises radiated engine noise and increases mechanical reliability. The V8's exhaust system has also been completely retuned to remain quiet at cruising speeds but deliver a substantially more purposeful V8 roar under hard acceleration.

In naturally aspirated form it develops 219kW (DIN), and 411Nm of torque. The supercharged version uses a highly efficient rotor-type supercharger, belt-driven from the crankshaft. It develops 306kW (DIN), and 560Nm of torque from low engine speeds. Just as important as the supercharged engine's peak torque is the way the usable torque is spread across a wide rev range - with at least 86 percent of the peak from 2000rpm to maximum engine speed.

A superior six-speed automatic transmission - renowned as one of the best in the world and already proven in other Jaguars - is used on all versions of the new XF - there is no manual gearbox option. The transmission is a key element in the XF's sporting character, its adaptive gear-changing strategies responding both to road conditions and the way the car is being driven, giving the smoothest shifts and optimum performance. Adding another layer of driver focus, the transmission is controlled by the new JaguarDrive Selector™ with the option of manual selection through Jaguar Sequential Shift™. The JaguarDrive Selector™ is also used to access the XF's Sport mode which uses shift-by-wire technology pioneered on the XK.

These high-tech, modern powertrains give every XF model outstanding performance. The 2.7-litre V6 diesel reaches 100kph in just 8.2 seconds and has a top speed of 229kph. The 3.0-litre V6 petrol version sprints to 100kph in 8.3 seconds and goes on to reach 237kph. The naturally-aspirated V8 model has a superb 0-100kph time of just 6.5 seconds and has an electronically limited top speed of 250kph. Lastly, the supercharged SV8 XF storms to 100kph in 5.4 seconds and, like the naturally aspirated V8 is limited to a maximum of 250kph.

DRIVING DYNAMICS

Delivering the highest levels of driver enjoyment is a must for any Jaguar, so it is essential that the XF's driving dynamics live up to its powerfully athletic looks. Underpinned by the stiff platform, wide track and finely resolved suspension, steering and brakes, the XF's dynamic flavour combines the comfort and refinement of a luxury saloon with the grip, balance, responses and stability of a sports car. The result is a dynamic character that delivers real driver involvement, as far removed from the premium saloon crowd as are the XF's bold looks.

Chief Engineer, Vehicle Integrity Mike Cross explains the development processes behind the new car:

"Two key objectives defined the XF's dynamic flavour - firstly that its driving abilities should match its sporting coupe-like looks, and secondly that it should have Jaguar's unique balance of ride, handling and refinement. The XF succeeds on all counts and the result is a very special experience."

Every XF model uses Jaguar Sequential Shift™ transmission control, allowing manual gear selections in the automatic transmission via 'paddle' switches mounted on the rear of the steering wheel, in either Drive or Sport mode.

But sporty is only half the XF driving dynamics story - refinement is equally important, and equally impressive. With its stiff shell, smooth powertrains and extraordinary attention to acoustic management (including a secondary bulkhead and dual-isolated subframe on all versions), the XF has outstanding NVH performance to match the best in class. At 50kph, for instance, the interior noise level is only 65.6dB, below its nearest BMW 5 Series rival, even when the XF is on larger wheels. Special attention has been paid to the V6 diesel model, whose sound quality is so impressive it is hard to tell what engine lies beneath the bonnet. The V8 XF takes lessons from the XK with an exhaust system tuned for an overtly sporty sound quality, especially when accelerating hard - again, just as the looks promise.


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