In our 4×4 training courses, we emphasise the importance of tyres. Regular inspections are vital for continued and efficient performance of vehicles. If you don’t have time to inspect your vehicle fully, then at least check your tyres.
Look at the place where the tyre touches the ground and estimate how much is making good contact with the road surface. You will find that it is about the size of your open hand. Essentially, four of these hand prints are keeping your vehicle in contact with the ground. Only the correct pressure ensures this contact patch.
Maintain your tyres at the vehicle manufacturer’s recommended pressure for the size and type fitted. Do not go by what is written on the tyre; for instance, your tyre may have written on it “50 psi cold”. This means that the tyre can hold a maximum pressure of 50 pounds per square inch. Do not inflate over this pressure; as it poses a safety risk and may result in tyre failure.
Running tyres under-inflated is also dangerous; it is the leading cause of blow-outs.
Check when Cold
You get a true pressure reading when the tyre is “cold”; which is why you should check them first thing in the morning. As soon as you start to drive the air inside the tyre begins to heat up due to the friction between the tyre and the road surface. Air expands as it gets warm and therefore, with nowhere to go, the tyre pressure goes up which will affect your reading.
Once you have figured out your required tyre pressure, you need to maintain them at that pressure. Your best bet is to buy yourself a good quality tyre pressure gauge. A “pen” type fits into a glove box easily and as long as it is kept free from dust etc., it will keep its calibration for a few years.