Jaguar unveil XF Diesels

By Simon McBride 30 December 2008

Jaguar has taken the wraps off the XF diesel. Perfect for the fleet manager the XF has now become an oil burner and could be just the job for long motorway journeys. But this oil burner has a sporty look, it sits on 19 inch wheels, it has an aerodynamic boot lid spoiler, there’s also discreet 'S' badging that according to Jaguar defines the car’s sporting luxury. Powered by a 275PS engine, the Diesel S gives the XF outstanding levels of performance, accelerating from 0-60mph in just 5.9 seconds, 1.8 seconds quicker than the excellent 2.7-litre model. In-gear acceleration is equally impressive, with a 50-70mph time of just 3.2 seconds. The maker has limited the maximum speed to 155mph. The car features parallel sequential turbochargers to help deliver the high levels of power and torque while the engine is matched to Jaguar's sophisticated six-speed ZF 6HP28 automatic transmission.Ron Lee, Group Chief Engineer, Powertrain, "The new parallel sequential turbocharger system on our new V6 diesel delivers V8 levels of performance from very low revs. It's a power unit that offers superb flexibility and remarkably low fuel consumption and emissions, while building on the refinement that has become a trademark of our Jaguar diesel engines." Jaguar has also launched a 240PS version of the new 3.0-litre engine, which produces 16 percent more power and a 15 percent increase in torque over the 2.7-litre diesel, allowing the XF to reach 60mph in 6.7 seconds. Its 50-70mph time of just 3.7 seconds, that’s only fractionally slower than the 275PS Diesel S model. While the maximum speed is 149mph. And like the 275PS engine, these great performance leaps are achieved with combined average fuel consumption of 42.0mpg – an improvement on the 2.7-litre diesel of over 10 percent – and a CO₂ emissions rating of only 179g/km. Mick Mohan, Jaguar Programmes Director beamed, “With CO₂ emissions of 179g/km, 42mpg average fuel economy and 0-60mph acceleration in 5.9 seconds, this is another great example of Jaguar delivering unrivalled performance while at the same time taking the level of refinement in diesel engines to a whole new level." While Mike O'Driscoll, Managing Director, Jaguar Cars said, "The new XF V6 Diesel S – combining superb performance and excellent fuel economy – sets the pace with acceleration from 0-60mph in 5.9 seconds, a maximum speed of 155mph, yet delivers an average fuel consumption of 42mpg and CO₂ emissions of 179g/km: Truly the best of both worlds!" Drawing on the experience Jaguar has gained in designing the original, acclaimed 2.7-litre engine, the new 3.0-litre AJ-V6D Gen III diesels demonstrates that it is possible to deliver improved performance, while reducing CO₂ emissions and fuel economy. In the XF, the new engine produces 10 percent less CO₂ than the 2.7-litre, while power has increased by 33 percent in Diesel S guise. As well as tackling CO₂, the new 3.0-litre engines meet the forthcoming EU5 regulations, due to come into force at the start of 2011. And these great performance leaps are achieved with combined average fuel consumption in both models of 42.0mpg – an improvement on the 2.7-litre engine of 12 percent. A key feature of the new engine is the parallel sequential turbocharger system, the first of its type to be fitted to a V-engine anywhere in the world. Delivering high torque throughout the entire engine rev range, Jaguar claims that there is improved throttle response and low CO₂ emissions. According to the luxury maker the twin-turbochargers work sequentially to deliver unrivalled response and best-in-class torque – an impressive 61 percent more than the 2.7-litre diesel from 1500rpm – while packing a huge punch at higher engine speeds. For most day-to-day driving, including motorway cruising, a responsive, variable-geometry primary turbocharger does all the work, while the smaller, fixed-geometry, secondary turbo is dormant, saving energy and improving efficiency. When the engine revs climb above 2800rpm, the secondary turbo is brought on line within 300 milliseconds, smoothly and seamlessly boosting the engine output with no discernible turbo-lag or power-step. The XF is fitted with a new commonrail fuel-injection system delivering up to five injections on each cycle at a pressure of 2000bar. Each injector tip is perforated by seven holes through which finely atomised fuel is sprayed into the cylinders. The high-pressure injection increases power, this improves economy and reduces both CO₂ and particulate emissions. New, third-generation high-speed piezo injectors allow up to five precise injection events during each combustion cycle, minimising engine combustion noise. The boffins at Jaguar have have achieved EU5 emissions regulations ahead of the 2011 legislative timetable using conventional diesel oxidation catalysts and diesel particulate filters (DPFs). NOx levels are reduced at source through the combustion system design, the addition of the new commonrail injection system and the new EGR system with by-pass. As a result, specialised NOx exhaust after-treatment is unnecessary, avoiding a potential cost and the need to use additional precious metals in the exhaust system.Mike O'Driscoll, Managing Director, Jaguar Cars concluded, "The new XF challenges the rules and redefines Jaguar sporting luxury. Our designers and engineers have worked together to develop elegant, inspired solutions to complex technical challenges. It's a simple but very effective philosophy and the result is great new products like the new 3.0-litre diesel XF." Simon McBride