Tyres

To blow or not to blow one gets often asked in the bush.

Sand and mud

Long long time ago an old farmer in the Kalahari told me the following:” The heaviest load on any car in the sand, is hard tyres”. And it is true to this day. When you going to enter a sand track or dunes, let 50% of the air out of the tyres to say, 1,5 to 1 bar, depending on the load of your vehicle. The lighter your vehicle is, the lower you go. If you tow a trailer or caravan, their wheels need to be deflated as well. You are increasing your “footprint” on the sand surface, spreading the car’s weight over a bit of a wider area. In extreme cases you can go very low but not below 0.6bar (not advisable) No sharp turns in the sand at very low pressure or your tyre may debead, climbing off the rim. Hit the brakes only in emergencies. Rather let the car come to a stop by itself. Hitting the brakes will build you a wall of sand ahead of the wheels. Reverse a bit and then forward building a bit of momentum to overcome your sand wall. This is not a rally race, so drive at a safe speed in 4 wheel high. Also be aware that the pressure and heat build up in the tyre as you progress through the day in long sandy stretches. 1,3 bar now but a couple of hours later, you are close to 2 bar again which may be one of the reasons why you are battling again in negotiating the sand spoor. When you are safely out of the sand area, pump the tyres to the specified pressure of your vehicle. Just check that pressure again in the morning as the wheels cooled down and the pressure will be down.

Rocky terrain.

There are 2 schools of thought on what the pressure must be. One says hard, the other says say soft. Me, I am a softy. There is a saying that it is difficult to cut a soft overripe tomato with a sharp knife. Over rocky terrain, you drive slowly and let the tyres wrap themselves around the edges of the rock. Take caution that the sidewalls are thinner and closer to the rocks and may cut them like an iceberg that cut the Titanic. Therefore, always be aware of where your wheels are and what can harm them. Drive as slow as possible but fast as needed.

Gravel road

If your car can, select 4 High as you will have more control over your vehicle on gravel. Deflate 15 to 20% of the air out of the tyres. 2 to 1,5bar, again depending on the heaviness of the vehicle. Again, you are not a rally driver, so drive carefully and be courteous to other road users with dust and flying rocks.  An interesting note is that most tyres on cars that get punctured are left rear tyre. No one can say why.

Happy traveling.

Peter Rau