How is car tire pressure detected?

[LaSara]

Car tire pressure is detected through a tire pressure monitoring system. The tire pressure monitoring system can be divided into two types: 1. Indirect tire pressure monitoring system: It determines whether the tire is abnormal by the speed difference of the tires. 2. Direct tire pressure monitoring system: By installing four tire pressure monitoring sensors inside the tires, it automatically monitors the tire pressure and temperature in real time when the car is stationary or moving, and provides timely warnings for high pressure, low pressure, and high temperature in the tires to avoid traffic accidents caused by tire failures and ensure driving safety. The following is an introduction to correctly detecting tire pressure: 1. Choose a high-quality pressure gauge to check tire pressure, and do not use visual inspection or the method of kicking the tire to detect tire pressure. 2. The specific value of tire pressure should be based on the tire pressure marked on each vehicle. 3. Measure the tire pressure when the tires are cold. The reading of cold tires is the most accurate, and hot tires should not be deflated or depressurized.

[Mallory]

I've been driving for almost twenty years and have witnessed several changes in tire pressure monitoring. In the early days, we relied on mechanical tire pressure gauges, requiring manual measurement by crouching beside each tire—sometimes the needle would get stuck, leading to inaccurate readings. Nowadays, most vehicles come equipped with built-in tire pressure monitoring systems (TPMS), where sensors are mounted inside the wheel rims, displaying real-time pressure values on the dashboard while driving. Last month, when I went to patch a tire, the technician showed me the new valve stem sensors—no larger than a coin but with a five-year lifespan. He recommended manually checking the pressure once a month, especially during seasonal temperature swings, as the system can have slight delays. I keep an electronic tire pressure gauge in the glovebox and test each tire before long trips, keeping the margin of error within 0.1 bar.

[DeLucy]

Last week I changed my car tires myself and took the opportunity to research tire pressure monitoring systems. There are two mainstream types: Direct systems have sensors inside each tire - my car has four transmitters that send real-time data to the dashboard. Indirect systems use ABS wheel speed sensors and trigger an alert when one tire rotates faster. However, the latter responds slower - once I drove 3 kilometers with a nail puncture before getting an alert. Nowadays you can buy external sensors on Taobao for just tens of RMB that screw onto the valve stem and display data via a phone app. But be careful with aftermarket parts - avoid no-name brands as a friend had a cheap one fly off at highway speeds. Regular calibration is crucial - I cross-check with a mechanical gauge every three months.

[ElianaFitz]

In our car enthusiast group, we often discuss TPMS (Tire Pressure Monitoring System) modification solutions. The OEM system is too expensive, while there are many aftermarket options: valve stem caps with color-changing warning rings that turn yellow when pressure is abnormal; solar-powered TPMS displays that stick directly to the dashboard; and smart sensors that allow monitoring via mobile apps. I use an external type that takes just two minutes to install and displays real-time temperature and pressure on my phone while driving. However, dynamic balance issues should be noted - last time when I sped up to 140km/h, the steering wheel shook, which was resolved by adding counterweights. Increasing tire pressure by 0.2bar in winter can save fuel - my actual test showed a reduction of 0.5L per 100km.