Conventional 2-wheel drive vehicles are at a big disadvantage to 4WDs that can, at the drop of a hat, charge off the beaten track to tackle a range of terrain challenges. However, owning a 4WD isn’t just about looking the part, but practical knowledge and skills around how to tackle these different terrains is the key to staying safe. Three aspects of four-wheel driving form the core of this knowledge: understanding the mechanics of your transmission, the role water and dust plays on traction, and the focus of this article, tyres and the important part they play in safely navigating every terrain type.
Sand conditions are the single biggest factor in 4WD beach driving. The general rule for all beach driving is to maintain a reasonable speed and stay in high range 4-wheel drive, with low range advisable in the event of getting bogged. Hard sand conditions make for easy driving but when you’re dealing with soft wind-blown sand you will need to concentrate on maintaining traction and keeping a consistent momentum to avoid getting stuck. This involves constant throttle control and high power.
Tyre deflation is a tactic that’s seen many a relieved 4WDer get out of trouble. The principal is that of increasing the surface area (footprint) of the tyre that’s in contact with the ground (but avoid deflation below 16psi). Remember, normal road rules apply on the beach – don’t speed, drink, or forget to use your seatbelts. The beaches that do allow driving all have different speed limits so be sure to educate yourself before setting off.
‘Mudplugging’ is a rather grand term for the type of mud encounters that most 4WD enthusiasts will experience, but the core principle remains the same for all: always keep your tyres on the highest ground (keeping your diffs out of the mud). If you start to slip down into a rut, continue to accelerate while steering from side to side. This will bring the lugs on your tyre sides into play to grab onto the rut sides for traction.
Always be inspecting your wheel arches for clogging – this greatly reduces your tread grip effectiveness. Clear out your guards and arches whenever necessary.
Besides snow driving, water crossings can be the biggest cause of anxiety for new 4×4 drivers. Scenes of rivers in full flood can play on the mind but drivers can be assured in a simple technique required for a successful crossing. A quick crossing on foot along the best lines for the 4WD provides a plan of attack (potential obstacles can be spotted this way).
Start out in first gear with low range, and don’t change gear mid-crossing because water can get inside the clutchplate doing this. Make sure your air intake will be clear of the water when you’re at the deepest part of the crossing. Keep a consistent speed throughout in order to get a nice bow wave spreading out before you as you cross.
After you’ve crossed give your tyres a good visual check in case objects hidden under the water have caused damage to the tyres.
Using the same technique as with mud, when 4WD rock climbing it’s crucial to keep your tyres on the highest parts on the ground at all times. This is to avoid hanging up and getting marooned on rocks, and also to prevent damage to the underside of your vehicle, protecting the diffs, transmission and bash plates. Torque over power is the rule of thumb with 4WD rock climbing, selecting low range and first or second gear while carefully easing over obstacles while avoiding tyre slip-inducing sudden acceleration.
Tyre pressure should remain the same as with open road driving, unless you are forced to reduce tyre pressure as a tactic to get out of a jam, by increasing tyre footprint contact. Tyre deflation leaves them greatly exposed to damage however, so take care until you can reinflate.
4WD drivers experience far less anxiety that 2WD drivers when it comes to snow. Light snow isn’t a problem with tyres easy crushing through the snow crust to gain traction on the underlying surface. There’s no need for chains with 4WDs until you hit deep snow.
When driving, select a high range and avoid sudden braking and acceleration. Maintaining a constant pace and avoiding sudden turns of the wheel is key to not finding yourself in a slip or a spin. Don’t rev your engine in deeper snow and use low range, patiently allowing your tyres to bite and gain traction rather than panicking and hitting the pedal. Always use snow chains when you reach a degree of snow cover that you’re not 100% comfortable with, it’s better to be safe than sorry!