I'm going to let you into a secret. I've tried countless 4x4's and I wouldn't normally dream of taking any them on to the sort of rough stuff their manufacturers claim they're designed to handle.
Of course manufacturers lay on off-road driving opportunities at launch events for their new SUVs. These involve following a short, marked course that has the cars leaning at crazy angles as they negotiate fierce-looking obstacles, getting very muddy in the process.
But you always feel anything that could get the cars into serious trouble has been left out.
Opportunities to practice off-road driving in Britain are limited so I jumped at the chance to join experts from Land Rover on a recent expedition designed to explore the capabilities of the Discovery 3 over a couple of days on the demanding terrain of the Icelandic interior.
Some of you will already be reaching for your pens to complain as you picture an unruly mob of irresponsible journalists going mad in big, heavy 4x4s, churning up irreplaceable, unspoilt Nordic landscapes.
So let me say up front 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 link 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.
Deep longitudinal ruts have developed in places; you have to choose between driving with your wheels in these grooves, putting up with an occasional noisy grounding, or 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 slush, snow and ice.
Using 4x4 vehicles under expert guidance gave us the opportunity to reach some spectacularly beautiful parts of Iceland that would normally be inaccessible. Almost every coffee stop provided 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. I saw a road sign after one fuel stop informing motorists that the next fuel supply was 243km ahead.
Very cold indeed
And it gets very cold indeed. Thank heavens a plan to spend a night in tents high 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 getting its own back.
Along the way I picked up quite a few interesting off-road driving techniques; for example, the best way to tackle a long, deep snow drift is not to crawl into it but to hit it at speed, relying on momentum to carry you through. One particularly difficult drift - about 30m long and more than a metre deep - was overcome using this method.
And I'll know it's best to break the ice before fording a frozen river to avoid getting stuck.
Advanced features
But the Discovery does a lot of the hard work for you. Advanced features such as air suspension, which can be raised to clear obstacles, and the terrain response system that automatically sets up the car's all-wheel drive and ride height for different conditions, do quite a good job of narrowing the gap between off-road expert and novice.
I'd previously only driven the petrol Disco but found the diesel to be a much nicer machine.
I suspect some of the Discovery's competitors - best described as pseudo off-roaders because they do without even basic features such as 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 Harrod's but if you ever have to drive across Iceland it's almost certainly your best bet.
Iceland
The population of Iceland was 273 577 at the end of 2004, living on an area of 103 000 sq km, of which 23 percent is vegetation, three percent lakes, 12 percent glaciers and the rest uninhabitable.
According to the official Icelandic government publication "Iceland in Figures 2005-2006" there are 2.9 people per square kilometre. - The Independent, London