Final answer:
When temperatures drop, tire pressures decrease. This occurs because the air inside the tires contracts with the cold, which in turn lowers the tire pressure. It is recommended to check tire pressure when the tires are cold for accurate adjustments.
Step-by-step explanation:
When temperatures drop, tire pressures decrease. This is due to the relationship between gas pressure, temperature, and volume, which is described by the ideal gas law. In colder weather, the air inside the tires contracts, leading to a lower tire pressure. Conversely, as the car is driven and the tires flex, their temperature increases, causing the tire pressure to rise.
It's important to note that most manufacturers specify optimal tire pressure for cold tires. This means it's advisable to check and adjust your tire pressure when the tires are cold to ensure accurate readings and maintain proper tire function and safety.