Why is there a discrepancy between the tire pressure monitoring system and the air pump display?
2 Answers
Strictly speaking, any instrument will have some degree of error. Between the air pump pressure gauge and the tire pressure monitoring system, the tire pressure monitor is more accurate. Here's relevant information: 1. Tire pressure range: Cold tire pressure of 2.3, 2.4, or 2.5 bar is normal, and after driving some distance, 2.5 or 2.6 bar is considered normal - it should not exceed 2.8 bar when the pressure is high. 2. Considerations: When tire pressure is high, the contact area between the tire and the road is smaller, resulting in poorer grip, longer braking distances, more noticeable bumps, and reduced comfort, but with lower rolling resistance and relatively better fuel efficiency. When tire pressure is slightly lower, the contact area with the road increases, improving grip and comfort, but with higher rolling resistance and increased fuel consumption.
I found that the readings from the tire pressure monitoring system and the air pump often don't match, mostly because the air pump itself has poor accuracy. Ordinary portable air pumps may not be precise, with errors reaching 2-3 psi, while the vehicle's built-in tire pressure monitoring system is calibrated and more reliable. I recommend first checking the accuracy of the air pump using a professional pressure gauge or confirming it at a service station to avoid misleading operations. Also, weather factors are important—tire pressure increases when driving in high temperatures, and measuring after the vehicle has cooled down will show lower readings, while the TPMS can display real-time values. It's best to compare readings in the morning when the vehicle is cold, as the difference will be smaller. Regular maintenance of the air pump to avoid long-term dust buildup affecting readings can also reduce this issue. If inconsistencies persist, don't overlook TPMS battery issues—sometimes, low sensor battery levels can display unreliable data, affecting driving safety.
