The Land Rover Discovery 4 gives the F-word a new dimension. For example, the engine in this muscular four-wheel-drive SUV is basically the same as the one that spirits and sprints the Jaguar XF and XJ luxury sedans.

Isn't it extraordinary that a three-litre diesel engine can support the demands of pulling a trailer or traipsing across muddy/rocky hillsides - and provide the smooth, fashionable impetus for a head-turning Jag?

The downstream mechanics in the new-generation Discovery 4 and the Jaguars completely change the character of the vehicles and their performance, of course, but it just goes to show the multiplicity of uses to which basic engine configurations are being put.

Apart from the clientele of both marques being sufficiently well off to buy these machines, the tasks asked of the respective vehicles are poles apart. Which is where the F-word comes in. It's called Flexibility.

In the Discovery the F-range is more varied than most, as this new version has to meet significant off-road as well as on-tarmac demands.

First they gave it a real going over for everyday users. The new twin-turbo engine makes a huge difference, not just in power and low-rev grunt, but also in quiet smoothness.

The cabin is now getting on for Range Rover status and the seats are much more comfortable. The Discovery has pulled up its socks to compete with the large SUV world.

It has, however, far more off-road ability than many of its more fashionable rivals. For instance, I could change the response to, and ability of, the vehicle to cope with a variety of conditions at the twirl of a dial.

I could have set it up for travelling on grass, gravel, snow, sand, crawling over rocks, through mud and ruts, slippery patches as well as for ordinary tarmac. As well as that, it had hill descent control, which keeps it from "running away" down steep slopes.

Now all this may sound to you like Land Rover has got it sussed mechanically. And it has, to a large extent. There is no denying the level of accomplishment. I thoroughly enjoyed driving it.

But it would be remiss of me not to mention that previous incarnations were not always a shining example of reliability. As such the Discovery still has some way to go to convince it has turned the corner as an overall package.

In addition, I suppose, this is not a great time for SUVs because of the price involved, our economic woes and the concentration of purchases in the small-car area so I'm sure Land Rover is not anticipating a flood of sales.

All I can tell you now is that with the Discovery's new twin-turbo three-litre diesel (based on the old 2.7-litre) there is a big increase in pulling power and a reduction in fuel consumption, noise and body roll, so this does make a fresh case on its own merits. For most, that legendary off-road ability boils down to relatively simple tasks.

EASY TO DRIVE

Families travel together (the Disco has seven seats), so while the strong-man work of the vehicle underpins its relevance, it has to be complemented by the comfort of a sedan.

That is why Land Rover has redefined the on-road dynamics. The new six-speed automatic transmission helped a lot too.

I was surprised at how well it drove and handled. I had just got out of a large executive sedan and expected a huge gap but there wasn't one. And it can move, believe me.

A lot of people are put off these big machines simply because they are so overwhelming. Yet the Discovery was easy to drive, with good steering feel and plenty of overtaking power.

It is not as ubiquitously fashionable as the likes of the Toyota Land Cruiser, but, previous record aside, it has to be taken far more seriously now. It hasn't so much grown up as matured. - Irish Independent