Underinflation

Underinflation is the condition in which a tire's inflation pressure is below the vehicle manufacturer's recommended level. It is typically diagnosed with a tire pressure gauge and is monitored in many modern vehicles by a tire pressure monitoring system (TPMS).

Causes include slow leaks from punctures or valve stems, improper seating of the valve core, seasonal temperature changes, and repeated inflation and deflation during maintenance. A tire can gradually become underinflated as air leaks or as the load on the vehicle increases.

Consequences include increased heat buildup within the tire, accelerated tread wear, and higher rolling resistance. This reduces fuel efficiency, worsens handling and braking performance, and raises the risk of a tire failure or blowout, particularly at high speeds or under heavy loads.

Detection and maintenance: Check tire pressures when tires are cold, and verify all tires (including the spare) are inflated to the manufacturer's recommended cold pressure. Use a reliable gauge; do not rely on the tire sidewall maximum pressure. If a tire remains underinflated after inflation or shows signs of leakage, have it inspected or repaired by a professional. Modern TPMS warnings should prompt inspection.

Prevention: Regular pressure checks, including before long trips and in extreme temperatures; proper load distribution and seasonal adjustments; promptly addressing punctures or valve leaks; replacing worn tires.