24/03/08

• Price51,542
• We like...smooth, smooth diesel
• We don't...dinner-plate alloy wheels

Despite tradition, diesel-powered Jag is the  pick of the XJ6sDrive a Jag and you are hard-wired into the past. XJ6s have been with us through five decades, and elements of the 1960s original are plain to see in this 2008 model. The snug cabin with its broad tunnel between the front chairs, the high window line, and the bulbous bonnet curving away as you drive: it’s all there.

But, for all that, the current one reaches into the future with its aluminium body that saves weight, its air suspension and, most surprising yet, the fact that the best XJ you can buy right now is.... diesel-powered. Yep. What would once have been a shocking prospect for any Jaguar fan is now just how things are.

And the twin-turbo 2.7 V6 is a honey. This engine is quick, responsive and silky-smooth, just as a big Jaguar should be, and it’s mated to an auto transmission that shuffles its six gears so softly, you scarcely notice. But – and this is probably the best bit – it ds all that and returns 35mpg. And even its CO2 emissions at 214g/km aren’t too bad for what it is. The XJ6 is a vast car, but its fuel economy is thanks in part to its modest 1635kg kerb weight, making it way lighter than most luxury-class rivals. But despite its 5.1-metre length, its cabin has only just enough space for five, while the boot is long but too shallow.

The XJ6 smothers the bumps with the composure and control you’d want from a Jag, although the vast alloys and skinny-sided tyres on our Sport model pulled the car off course as it travelled over road markings or ruts left by lorry wheels.

The car is packed with equipment, much of which is controlled by a touch-screen monitor sited centrally and low in the dash. But despite this, the cabin is home to no fewer than 87 buttons to control this and that. We spent a long session studying the owner’s manual but came away still wondering about a few. We also noticed that it was too easy to activate the touch screen by mistake while you were prodding the switches surrounding it.

The XJ6 is keenly priced against its main rivals, the Mercedes S-class and BMW’s 7-series. It’s such an appealing car that you’d expect to see more on the roads. We don’t, and that’s a puzzle and a pity.

But, if the new Jaguar XF is as good as is promised, let’s hope its success will revive interest in its big, charismatic brother.

• Engines2.7 V6 twin-turbo diesel
• Power204bhp
• 0-60 mph7.8sec
• Economy35.0mpg
• CO2g/km214
• Insurance groups15
• EuroNCAP
• Airbags8
• Seats5

Motors.co.uk value verdict: