Tire pressure fluctuates with temperature. Checking tire pressure is a routine part of maintenance for automobiles. It can sometimes be confusing when the pressure increases by several psi (pounds per square inch) after driving and then decreases after being parked for a few hours.
Road Friction – Friction between the tire and the road increases tire temperature. When your car is driven, friction is produced between the tires and the road, creating heat.
Gay-Lussac’s Law – Temperature affects air pressure. Gay-Lussac’s Law states that temperature increases air pressure inside a container. This means that when your tires heat up, the air pressure inside them increases.