Are External Tire Pressure Monitors Accurate?
2 Answers
External tire pressure monitors are relatively accurate, but their precision is inferior to that of internal tire pressure monitors, as they are more susceptible to environmental factors. Advantages of External Tire Pressure Monitors: External tire pressure monitors are easy to install. However, since the sensors are exposed to the external environment year-round, they face more complex environmental challenges and are prone to being dislodged or stolen. Therefore, for car owners who frequently drive long distances, an internal tire pressure monitoring product is more suitable. Additionally, when driving at high speeds, the tires are in rapid motion, causing the gas convection speed to be very fast. As a result, the tire temperature readings from external tire pressure monitors may have a 1-2° error compared to internal tire pressure products, which is considered normal. Introduction to Internal Sensors: The batteries of internal sensors are generally encapsulated within plastic casings, making them impossible to replace by the user, whereas the batteries of external sensors can be replaced by the user. It is important to note that the battery life of the sensors is determined by the monitoring interval, tire anomalies, and driving duration.
I've used several external tire pressure monitoring systems before, and from a safety perspective, accuracy is indeed important but shouldn't be fully relied upon. External sensors are installed on the valve stems, and if not securely mounted or due to bumpy roads, readings can easily drift. Pressure deviations are significant with temperature changes—for example, readings tend to be higher on hot days and lower on cold days, which can be misleading and risky. I've found that cheaper brands have lower accuracy, with errors up to ±3 PSI, affecting tire lifespan and the risk of blowouts. I recommend regularly using a mechanical gauge for manual verification, especially before long trips, to ensure consistent tire pressure. Although built-in systems are more stable, external ones are easier to install and more cost-effective. The key is to choose reputable brands and maintain them well. Neglecting accuracy can create hidden dangers, so I check mine weekly to ensure safe driving.
