For a truck, tires are like its feet, carrying the weight of the entire vehicle and the only part in contact with the ground. When describing the subtlety of tai chi, there is a saying "four ounces can deflect a thousand pounds", and the small tires can carry the weight of tens of tons, demonstrating the same principle! Tires rely on the air filled inside to maintain support and cushioning. Once the air is lost, the carrying capacity of the tire is almost zero, so the more air there is inside the big truck tyres, the greater the pressure, and the more weight it can carry.
Both overinflated and underinflated tires can cause a blowout. From usage habits, underinflation is more common and harder to detect. Overinflation only happens during air-filling, and in reality, a tire pressure gauge is used during air-filling, making the probability of overinflation very low.
Moreover, big truck tyres undergo tire pressure testing before leaving the factory, and tension application is a relatively static process. Therefore, tire blowouts caused by overinflation often occur after long periods of high-temperature driving or severe impacts. The most direct feeling of overinflation is the increase in the vibration degree of the vehicle, the decrease in comfort, and the abnormal wear of the tires, which mainly aggravates wear in the middle part of the tire tread. However, tire failure or foreign objects embedded in the tire can also cause slow air leakage, and this kind of leakage is slow and hard to notice, making it similar to a chronic disease for tires.
Keep in mind that the weight of the vehicle depends on tire pressure. Underinflation causes excessive bending of the sidewall, resulting in wrinkles. Long-term driving with low tire pressure can cause rapid aging of the sidewall, with continuous peeling of the rubber and tire cord layer until the sidewall completely cracks open. Low pressure combined with high-temperature driving is like the tire having an acute illness, which can result in a fast and violent process of a blowout.
What is the appropriate tire pressure for truck tires? We can refer to the air pressure label on the tire sidewall. The maximum value shown on the tire pressure label is generally the limit and is a reference value in cold tire conditions. As the tire temperature increases, the tire pressure increases as well.
It is recommended to not exceed the maximum safe air pressure and maximum load indicated on the tire when hauling or inflating, but some truck drivers say they have inflated the tire pressure beyond the maximum safe air pressure on the tire. This may be due to errors from the tire shop itself where it might say that 10 units of air is put in, but in reality, there might only be 9.5 or even 9 units of air in the tire.
It is suggested to keep a portable electronic tire pressure gauge as they are relatively accurate and not expensive, costing just tens of dollars. After inflating the tire, one can use a more accurate electronic tire pressure gauge to double-check, reducing wear on the tire, and saving money on tires.