Earlier in 2009 Jaguar's much-lauded XF sedans were given heart transplants with the introduction of more powerful but economical new engines.
We recently reviewed the big daddy of them all - the supercharged five-litre petrol V8- and it shot to the top of the sports-sedan league with its class-beating acceleration, even managing to out-sprint the more powerful (but heavier) Audi RS6.
Some industrious engine tweaking has been done lower down in the range too, with the previous 2.7-litre turbodiesel being upped to a three-litre V6. There are two versions of the engine: a more emissions-friendly 177kW/500Nm derivative and a larger-fanged 202kW/600Nm unit that powers the 'S' model.
On review here is the more powerful of the two, in which Jaguar has managed to reduce fuel consumption by a claimed 10 percent and emissions by 12 percent despite a 33 percent increase in power.
The engine requires low-sulphur, 50 parts-per-million diesel, which is not always freely available. The warranty isn't affected but frequent use of high-sulphur fuel blocks the particulate filter, which affects performance, so the local auto industry is lobbying for more freely available 50ppm.
A key feature of the new engine is the use of two turbos to optimise power delivery across the rev range. Only the primary, variable-geometry turbo operates at lower rpm to save fuel and to reduce emissions but once engine revs climb above 2800 the secondary, fixed-geometry turbo comes on line, seamlessly boosting engine output with no discernible step.
The result is lively power delivery all the way through the rev range once the merest hint of turbo lag has been shaken off. We tested at Gauteng altitude but I suspect the lag will disappear at sea level.
As strong as the power delivery felt, the actual performance figures were a little disappointing as the 7.9sec 0-100 time we clocked was well down on Jaguar's claimed 5.9. I suspected it was the less powerful diesel model we were testing but nope, there was the "S" badge right there on the boot lid.
Curious, and perhaps the low-mileage engine was still tight but, nevertheless, by the seat-of-the-pants meter this is a gutsy-feeling car that deserves to be called a sports diesel.
It responds briskly to throttle inputs, overtakes long trucks like they were Fiat Unos and has an excellent six-speed auto transmission that swops cogs quickly and smoothly - even quicker when you press a button marked with a chequered flag, which gives the throttle and gearbox sportscar-like responses.
SILENTLY AS A NINJA
We never got close to Jaguar's claimed fuel consumption figure of 6.8 litres/100km, but our 9.4-litre average was still pretty impressive given this sports sedan's muscular performance.
It's definitely good enough to swing a few votes away from the petrol models in the Jaguar showroom, especially since it's such a refined diesel. The engine generally whispers along as silently as a ninja and even when idling it manages to hum a soft, non tractor-like tune.
No petrol engine will offer the same economy with performance. The XF 3.0D S is worth a serious look, even for the dedicated petrolhead.
The drivetrain gels harmoniously with the XF's all-round refinement and classy opulence, which has shaken off the antiquated feel of previous Jaguars. It's no longer just a car for silver-whiskered gents who say "tally-ho" a lot. - Star Motoring