Iceland's worst terrain is no match for the Land-Rover Discovery

Ice? No problem. Rocky roads? Tackles them with ease. David Wilkins finds that the Discovery 3 is perfect for an off-road adventure

I'm going to let you into a secret. I've tried out countless 4x4s for The Independent's Verdict and I wouldn't normally dream of taking any them on to the sort of rough stuff that their manufacturers claim they are designed to tackle.

Manufacturers do, of course, lay on off-road driving opportunities at launch events for their new SUVs. These tend to involve following a short marked course that has the cars leaning over at crazy angles as they negotiate fierce-looking obstacles, getting very muddy in the process, but there's always the feeling that anything that could get the cars into serious trouble has been left out.

Given that the opportunities to practise off-road driving in Britain are limited, I naturally leapt at the chance to join experts from Land-Rover on a recent expedition designed to explore the capabilities of the impressive Discovery 3 over a couple of days on the demanding terrain of the Icelandic interior.

Now, I know from past experience that some of you will already be reaching for your pens to complain as you picture in your minds an unruly mob of irresponsible journalists going mad in big, heavy 4x4s, churning up irreplaceable, unspoilt Nordic landscapes. So let me mention at once that most of our driving was not, strictly speaking, off-road, but took place instead on the sometimes challenging officially marked but unpaved roads and tracks that are the main means of linking Iceland's remoter parts. These vary enormously in quality; some feel as good as paved roads, while others are full of holes or strewn with rocks.

In places, deep longitudinal ruts have developed and you have to choose between driving with your wheels in these grooves, putting up with an occasional noisy grounding, or, on the other hand, slithering around trying to avoid them. Some of these tracks are only passable using a 4x4, and in winter everything is made a lot more difficult by the presence of slush, snow and ice.

Using 4x4 vehicles under the guidance of experts gave us the opportunity, of course, to reach some spectacularly beautiful parts of Iceland that would normally be inaccessible. Almost every coffee stop provided what could fairly be described as a once-in-a-lifetime experience; a walk on a vast glacier, a chance to see huge icy waterfalls, or, best of all, the ghostly Northern Lights.

The same few basic elements of the Icelandic winter landscape - volcanic rock, water, snow and ice - combine, depending on the light, to produce a surprising amount of variety. The population density is below three inhabitants per square kilometre - most seem to live in Reykjavik - and the distances between smaller settlements are vast. After one fuel stop, I saw a road sign informing motorists that the next filling station lay 243km ahead.

And it gets very cold indeed. Thankfully, a plan to spend a night in tents high up on the side of a snowy mountain was abandoned when conditions became too difficult. Man and his cars may be killing nature, but that evening, it felt like nature was, in a small way, getting its own back.

Along the way, I picked up quite a few interesting off-road driving techniques; I now know, for example, that the best way to tackle a long, deep snow drift is not to crawl into it, but to take quite a run-up and hit it at speed, relying on momentum to carry you through. One particularly difficult drift - about 30 metres long and more than a metre deep - was overcome using this method. And if I ever need to ford a river with a frozen surface, I'll know that it's best to break the ice before driving across in order to avoid getting stuck.

But while many of these insights are valuable, in truth, the Discovery does a lot of the hard work for you. Advanced features like the air suspension, which can be raised in order to clear obstacles, and the Terrain Response system, which automatically sets up the car's four-wheel drive system and ride height for different conditions, do quite a good job of narrowing the gap between off-road expert and novice. I had previously tested only the petrol Disco, but found the diesel to be a much nicer machine.

I suspect that some of the Discovery's competitors - best described as pseudo off-roaders because they do without even basic features like low-range gearing - would simply have shaken to bits. I'm still not sure I see the point of buying one just to go shopping at Iceland. But if you ever have to drive across Iceland it's almost certainly your best bet.

The Land-Rover Experience runs a number of off-road centres in the UK, including Eastnor Castle in Herefordshire. Courses are available that cater for drivers with all levels of experience, including the emergency services

Iceland

Iceland population: (end 2004): 273,577

Area: 103,000 sq km, of which vegetation 23 per cent, lakes 3 per cent, glaciers 12 per cent and waste 63 per cent

GDP per head (2003): $43,137 (one of the highest in the world)

Population per sq km:

2.9 (Based on data from the official Icelandic government publication "Iceland in Figures 2005-2006")

Land-Rover Discovery 3

Introduced in 2004, the Discovery 3 kept some of the styling themes of its predecessors but is otherwise entirely new. It is one of the most advanced off- road vehicles on the market.

The Terrain Response system allows drivers to select a suitable setting on a dashboard dial ("Sand", "Ice/Grass/Snow" etc.) and the car automatically adjusts the gearbox, differential locks and engine-management systems accordingly. The air suspension system also sets the ride height at the appropriate level. New petrol and diesel engines, shared with Land-Rover's sister marque Jaguar, are paired with six-speed manual or automatic gearboxes.

The Integrated Body Frame construction, which attempts to combine the advantages of a separate chassis with those of an "all-in-one" monocoque body, is heavy, but it also means that the Discovery's body is extremely strong and stiff.