The four circles of rubber connecting our vehicles to the road are one of the most critical components on any drive, on any terrain. Yet they are all too often overlooked, or simply taken for granted.
In reality, you are only connected to the road surface by an area of rubber the size of an A4 piece of paper. Take away the tread, and that contact surface is reduced to not much more than an A5 piece of paper.
Despite this small patch separating terra firma and disaster, all too often tyres are the one component (or four components) where 4×4 owners try to save a little money. Big mistake!
When selecting the correct tyre for your vehicle and your typical loads and speeds, look closely at the sidewall of the tyre where all the information you need to match the tyre to your application is imprinted. Apart from tyre size, you will also find load and speed ratings, date of manufacture, and type of construction. Learn where to find these markings, and what they mean (most tyre company websites carry tables to help interpret the codes).
When it comes to off-road driving, we tend to load a lot more on our vehicles and as such we need to use the correct tyre construction. Here LT (Light Truck) is the correct choice; it implies stronger sidewalls, more plies, and more rubber in the construction of the tyre. It is also extremely important to note the speed rating of your tyres, and to stay below that safety limit.
Tyres are your primary traction device. As such, one of the first principles of off-road driving is to deflate tyres in order to increase their footprint, resulting in improved traction. The length of the footprint increases as pressure drops, though of course tyres do bulge more on the sides (heavier sidewall tyres less than those with thinner sidewalls).
There is no specific pressure for certain terrain types. Rather, the ideal footprint is dependent on the construction of the tyre, and the mass of the vehicle (which will sometimes be more or less heavily loaded). For this reason, we steer clear of giving advice as to what actual pressures you need to utilise.
However, these percentages below standard inflation pressure are a rough guide…
· On rough terrain, slight under-inflation (approximately 10%) is preferable.
· To prevent ‘ploughing’ over loose sandy terrain, use 50% of the recommended inflation pressure. In this case, maintain very low speeds on short runs to avoid heat build-up in the tyres. In addition, refrain from any sharp turns with hard acceleration as you run the risk of de-beading the tyre.
· For normal sand driving (such as on the roads in Botswana and Mozambique), 25-45% under-inflation improves flotation.
· In mud and snow, pressure reductions over 30% are not recommended.
Once you have completed your drive, it is crucial to re-inflate your tyres to normal operating pressures.
Be aware that deflated tyres expose the sidewalls of your tyres, and this is where your tyres are most prone to cuts and punctures because the sidewall is a lot thinner than the tread. This is why one must be especially careful where you place the wheels when driving off-road.
When re-inflating tyres, take the time to check the tread and sidewalls, including the inside sidewalls where potential damage is less visible.
When it comes to repairing a punctured tyre out in the bush, remember that it is an emergency repair, whether the plug has been inserted into the tread, or (more dangerously, and as a last resort) into the sidewall. Once you are back in civilisation, it must be repaired professionally.
CRUCIAL TYRE CARE GEAR FOR OFF-ROAD DRIVING
Four vital items should be carried in your 4×4 at all times, all linked to tyres and tyre care. In each case, purchase the best quality items you can afford: they will be used often, and when you do need them, they must work optimally.
· Tyre deflator – digital or analogue
· Tyre pressure gauge
· 12V compressor
· Tyre repair kit