How Does Temperature Change Affect Tyre Pressure?
The relationship between tyre pressure and air temperature is based on Gay-Lussac's Law. The pressure of a gas at constant volume is directly proportional to its absolute temperature (in Kelvin).
Formula: P₂ = P₁ × T₂ / T₁ (temperatures in Kelvin: T(K) = T(°C) + 273.15). Practical rule: every 10°C drop in temperature reduces tyre pressure by about 0.07–0.09 bar. A tyre inflated to 2.3 bar at 25°C in summer may drop to ~2.0 bar at −10°C in winter — a 13% loss that significantly affects road safety.
Under-inflation hazards: Fuel economy declines by 1–2% for every 3 PSI (0.2 bar) drop, tire tread wears unevenly, braking distances increase, and overheating blowout hazards rise.
This calculator applies ideal gas laws to compensate for seasonal ambient temperature shifts, keeping tires safely at manufacturer specifications.