Text: Inigo S. Roces / Photos: Inigo Roces | posted December 11, 2010 00:12
The XF Diesels are available in Diesel and S trim. Both are powered by a DOHC 3.0 liter common rail turbo diesel. The S model benefits from a parallel sequential turbo system. Both are paired with a six-speed automatic transmission that delivers power to the rear wheels. The XF Diesel S is distinguished by 19 inch wheels, an aerodynamic boot lid spoiler, and discreet 'S' badging. It is targeted at the most discriminating client and the keen motorist looking for speed and efficiency.
Allowing the XF Diesel to do just that is the new 3.0 liter AJ-V6D Gen III diesel engine. The regular AJ-V6D engine produces 240PS while the Diesel S boasts of 275PS. The engine produces 16 percent more power and a 15 percent increase in torque over its 2.7 liter predecessor. This allows the XF to reach 100 km/h from a standstill in just 6.7 seconds, the top speed is electronically limited to 250 km/h. The 275PS version accelerates from 0-60mph in just 5.9 seconds. In-gear acceleration is equally impressive, with a 50-70mph time of just 3.2 seconds. Maximum speed is also electronically limited to 250 km/h. The new engine also demonstrates that it is possible to deliver improved performance, while reducing CO2 emissions and improving fuel economy. The new engine produces 10 percent less CO2 than the original acclaimed 2.7 liter engine, while power has increased by 33 percent in Diesel S guise. These great performance leaps are achieved with combined average fuel consumption in both models of 42.0mpg - an improvement on the 2.7 liter engine of 12 percent.
Accounting for the quiet, efficiency and lower emissions of the engine are the piezo injectors, that deliver more precise amounts of fuel, a compact graphite iron cylinder block that makes for a smaller, lighter but also more durable size and a new, water-cooled exhaust gas recirculation system that helps that engine warm up faster from a cold start and decrease the amount of unburnt gases.
"The key feature of the new engine is its unique parallel sequential turbocharger system, the first of its type to be fitted to a V-engine anywhere in the world," said Mr. Soong. "When the engine revs climb above 2800 rpm, the secondary turbo is brought on line within 300 milliseconds. But for most day-to-day driving, a responsive variable-geometry primary turbocharger does all the work, while the smaller-fixed geometry secondary turbo is dormant, saving energy and improving efficiency."
To put all this into more concrete terms, participants were enjoyed to experience the cars on track with
an air conditioned tent for those waiting, decked with delectable kapampangan food. The event employed the expertise of renowned racing instructors Georges, Menchie and Stefan Ramirez who had divided participants into groups for the exercises. The first group was to drive an XF V6 petrol through a short course consisting of a short strip, a u-turn, slalom and braking area. With that done they would be transferred to the short circuit portion of the track where participants could take the XF Diesel S on a full lap, with an instructor riding shotgun.
On the circuit, the XF Diesel S proved that it can switch smoothly from motorway-cruising to racetrack mode seamlessly with no discernible turbo-lag or power-step.