We all know that 4WDing with a group is not only a smart and safe way to get out and see the bush, it's also a heck of a lot of fun! But have you ever noticed that once the terrain starts to get a little tricky, there always seems to be one or two in the group that just do it all easily? While it's true that a well-set-up rig will help to some extent, more often than not it's the guy behind the wheel's ability to read the terrain and pick the right line that makes all the difference.

According to 4WDing icon Vic Widman, reading the terrain successfully "comes with practice and being aware of what is going on under your wheels. Some people know exactly what level of traction they will achieve, while others just charge through and haven't a clue what was really going on."

After reading this article, you should have a good idea of what to look for and how to tackle the various hazards that 4WDing can throw at you, and with a little practice, you'll be showing up your friends in no time at all!

KNOW YOUR VEHICLE

In order to get the best from your 4WD, you need to know its strengths and weaknesses. While it's not particularly sexy, you need to have a good knowledge of what's under your 4WD and where the lowest points are. For example, are the differentials in the centre of the axles or off to one side? Where is the transfer case located? Is it well tucked up or exposed?

You also need to know what the approach, departure and ramp-over angles are. The approach angle determines the steepest step that a vehicle can approach without its nose grounding, and the departure angle determines the steepest step that a vehicle can drive off without its tail dragging.

HOW TO READ THE TERRAIN

The main thing to keep in mind when 4WDing is that there can be no progress without traction, and the best way to maintain traction is to keep all four tyres on the ground at all times.

Unfortunately, even having all wheels on the ground does not guarantee traction. Lack of traction can be caused by the type of terrain, tyre pressures and the amount of weight that is on each wheel. If a wheel doesn't have much weight on it, then it's easy for it to break traction and spin. If one wheel on each axle breaks traction in a vehicle with no traction aids, no drive is sent to the wheels that do have traction and the vehicle has become a zero-wheel drive! This condition is known as being 'cross-axled'.

"Strive to keep wheel articulation to a minimum," advises Vic, "as this minimises the chance of losing traction and makes it easier for the fourby to tackle the obstacle."

Another difficulty with reading terrain is that what you are looking at while you're driving is at least 5m in front of you. That means you have to memorise what you were looking at before and remember the high and low points relative to where your 4WD is now. You also need to know where the low points are under your 4WD so that you avoid having any of its low points collide with any of the high points in the terrain as you pass over it.

ROCKS

Rock driving can be one of the most challenging aspects of 4WDing. It requires accurate wheel placement and a delicate touch of accelerator and brake pedals. It needs to be performed at slow speed to avoid serious damage to suspension, tyres, underbody components and body panels.