In winter, the tire pressure becomes 1.7 at 2.3 during the day and night. What happened?

The principle of thermal expansion and cold contraction. In winter, the tire pressure of automobile decreases, which is normal, mainly due to the principle of thermal expansion and cold contraction. In winter, as the weather gets colder, the air in the tires will also decrease, so if the car warns that the tire pressure is too low at this time, don't be too nervous. On the basis of automobile standard tire pressure, it only needs to be slightly raised by 0. 1bar to 0.2bar.