How accurate are TPMS sensors?

Accuracy of TPMS sensors

Direct TPMS

For direct pressure sensors, accuracy is usually within 1 to 2 PSI of the actual pressure in the tyre. They can pinpoint which tyre has lost pressure, as well as giving you real-time readings.

Indirect TPMS

Indirect systems are not as accurate, because instead of measuring tyre pressure directly, they measure it by inferring pressure based on the rotational speed of the wheel. They may only sense larger changes in pressure and do not always indicate which tyre is low.

Importance of manual checks

Regardless of type, the TPMS warning lights tend to only illuminate when pressure has fallen by 25 percent or more from the recommended level. By this point, the tyre is significantly underinflated, and unsafe to drive on. Monthly checks with a gauge prevent the tyre from falling to unsafe levels by catching smaller dips in pressure before they become a problem. This keeps the tyre in the optimal range and maintains the safety and efficiency of the car.