Is It Normal for the Four Tires to Have Different Tire Pressures?
2 Answers
It is not necessarily normal for the four tires to have different tire pressures. The tire pressures of a car's four tires cannot always be the same, but the difference between the front and rear tires should not be too large. Generally, a difference of around 0.1 bar is considered normal. Tire pressure monitoring involves real-time automatic monitoring of tire pressure while the car is in motion, alerting the driver to tire leaks or low pressure to ensure driving safety. There are three commonly used tire pressure monitoring methods: Direct Tire Pressure Monitoring: Direct tire pressure monitoring devices use pressure sensors installed in each tire to directly measure tire pressure. The pressure information is transmitted wirelessly from inside the tire to a central receiver module, which then displays the tire pressure data for each tire. The system automatically alerts the driver when the tire pressure is too low or there is a leak. Indirect Tire Pressure Monitoring: When the pressure in a tire decreases, the vehicle's weight causes the rolling radius of that tire to become smaller, resulting in a faster rotation speed compared to the other wheels. By comparing the differences in rotation speeds between tires, the system monitors tire pressure. Indirect tire pressure alert systems essentially rely on calculating the rolling radius of the tires to monitor pressure. Introduction to Tire Pressure Monitoring System (TPMS): TPMS combines the advantages of both systems mentioned above. It is equipped with direct sensors in two diagonally opposite tires and an indirect system for all four wheels. Compared to a fully direct system, this hybrid system can reduce costs and overcome the limitation of indirect systems, which cannot detect when multiple tires simultaneously have low pressure. However, it still cannot provide real-time data on the actual pressure in all four tires as a direct system does.
I think having four tires with different pressures is usually not a good thing. I often check my car myself, and if the tire pressures are inconsistent, it can affect the overall driving experience and safety. For example, if one tire has high pressure and another has low pressure, it can easily cause the vehicle to pull to one side or become unstable to control, especially on highways, which is quite dangerous. Additionally, tire wear will be uneven, with the shorter-lived tires wearing out quickly while the longer-lasting ones can still be used—isn’t that a waste of money? Ideally, all tire pressures should be kept within the manufacturer’s recommended range, usually listed on a sticker inside the car door. I measure mine every two weeks using a simple tire pressure gauge. High temperatures in summer or cold weather in winter can also affect tire pressure, so a quick check before heading out, along with regular maintenance, can save a lot of hassle. Remember, small differences like a few PSI may vary due to driving conditions, but large differences exceeding 5 PSI should be addressed promptly to avoid issues like leaks or suspension problems—waiting until something goes wrong is too late.
