what psi is too low

According to the search results, any PSI below the recommended number is technically too low. However, most consider a variance of more than ten percent to be too low. For a car requiring tire inflation to 35 PSI, a reading of 31 or 32 PSI is considered underinflated. The lowest tire pressure you may drive on is 20 PSI, but this is not recommended. A flat tire is defined as a tire with a pressure of less than 20 PSI. It is important to note that tire pressure can be lost without a tire appearing underinflated or flat, so it is recommended to check tire pressure regularly. Additionally, most cars are equipped with a tire pressure monitoring system that warns drivers if the pressure drops 10% below the specified PSI.