Jaguar XFs powered by the new 237bhp 3.0-litre diesel engine will not cost any more than the outgoing models - despite being more powerful and cheaper to run.
The new engine has 16% more power and 15% more pull than the 2.7-litre unit it replaces. It also emits 10% fewer carbon dioxide emissions, which will also reduce company car tax bills.
The higher-performance S version of the new engine, with 272bhp will cost 2700-3000 more than the standard engine, but delivers 32% more power and 61% more torque than the unit it replaces.
Running costs will also be reduced, because cars equipped with the new engines will only need servicing every 16,000 miles, rather than the current model's 12,500. The engines are also easier to maintain, so Jaguar says labour charges should also be reduced.