Jaguar XF S
New 271bhp V6 diesel engine takes Jaguar XF into faster territory
Jaguar has upped the XF's game by way of a new 3-litre diesel. The twin-turbo engine is offered in two states of tune - 237bhp and 271bhp - providing stiff competition for the XF's toughest oil-burning rivals, the BMW 530d and 535d.
The XF Diesel S, in its higher tune, boasts 443lb ft of torque and a 5.9sec dash to 60mph, while top speed is reined-in at 155mph. Average fuel consumption is 42mpg while CO2 emissions are 179g/km. In-gear acceleration isn't bad either, 50-70mph taking just 3.2sec. Compared to the 2.7-litre diesel XF, power is up by a third with emissions and consumption down by around a tenth. Torque at 1500rpm is up by a massive 61 per cent, so anyone upgrading will really reap the benefits of the new engine.
The new unit is pretty trick, with two turbos, one bigger than the other. The bigger, variable-geometry turbo does all of the work the majority of the time, being the sole provider of extra shove during a motorway cruise. A smaller, secondary turbo (which is fixed-geometry) lies dormant until you pass 2800rpm, when it starts working to provide a seamless flow of extra power.
A lot of twin-turbos use their smaller turbo more of the time, but by turning this on its head the new Jaguar XF diesel gains crisper power delivery while cutting carbon emissions and fuel consumption, two of the key reasons for choosing diesel. The secondary turbo takes just 300 milliseconds to play its part, so there should be no evidence of turbo lag.
The detuned, 237bhp engine boasts the same technology and reaches 60mph in 6.7sec before reaching 149mph. The 50-70mph sprint is half a second slower at 3.7sec, although the car's fuel economy and carbon emission figures are identical - with a price advantage set to be the reason to choose the lower powered car.
Prices themselves are yet to be revealed, but they will be higher than the current 2.7-litre diesel but are likely to undercut the £37k and £42k commanded by the BMW 5-series diesels in M Sport trim. You'll be able to tell the new XF Diesel S from existing variants via 20in alloy wheels, a discreet boot lid spoiler and some subtle S badging, although the car will also gain a more striking Portfolio version in the near future.