Jaguar's introductory model has luxury and performance – and now a new high-economy diesel. Can it be thrifty and enjoyable to own asks Matt Joy, of the Press Association.

It's a very busy time at Jaguar with the F-Type Roadster and Coupe prowling the streets and a new high-performance XJR but it's the more mainstream models that are relevant to most of us – which is why the XF is so important.

Jaguar has given the XF a few key updates for 2014 and, reflecting the times we live in, the most important change is the introduction of a more frugal new diesel engine. The 2.2-litre four cylinder unit improves on the previous version with impressive figures of 129g/km of CO2 and 57.7mpg combined – the kind of numbers that appeal to your wallet rather than your heart.

Part of the reason for the improvement is some clever techy stuff in the shape of a revised cooling system and a bigger exhaust gas recirculation (EGR) valve, but what makes greater sense to you and me is the stop-start system that cuts the engine out when not needed.

If you've not experienced stop-start it might feel a bit weird, but once you trust the engine will start again the instant you release the brake pedal it becomes second nature. It all helps eke out a few more miles per gallon. It's clever too – pull up and put the transmission in 'park' and it goes into stop mode, but release your seat belt and it knows you are home and switches off completely.

You still get the XF's bit of theatre when you start up too, as the air vents glide electrically open and the circular gearlever rises from centre console. The gearbox is a new addition too, with eight forward ratios. That might seem an awful lot, but it helps economy too – on the motorway the engine is barely above tickover at 70mph which keeps noise levels down and fuel economy up.

Despite its focus on economy, the XF still offers a driving experience that is a cut above the norm. Regardless of speed it feels poised, filtering out bumps so you are aware of them but without discomfort. The flipside is that when you press on the XF is trualy a sports saloon, gripping strongly and staying level and controlled through corners.

The XF is a car you would be happy to live with daily too. Seats are supportive and comfortable, the heated seats will toast your behind if you leave them on full power and a top-drawer audio system can make traffic jams seem irrelevant.

Once upon a time Jaguars were all about the cut and thrust and weren't so easy to justify financially. But the 2.2 diesel XF is as economical and easy to live with as a fairly humble family hatchback, yet gives you so much more in terms of comfort, style and driving pleasure. It's hard not to be very impressed.