When outside temperatures are stable, you should check tire pressure about once a month. When the weather brings rapid temperature changes, remember that every 10-degree rise or fall on the thermometer will change your tire pressure by at least 1 PSI. And if your vehicle has TPMS (most newer vehicles do), remember that it’s not necessarily a substitute for regular tire pressure check. Your TPMS may be designed only to alert you to sudden pressure loss, or to a specific low pressure measurement. Even moderately low pressure can increase the chance of a blowout, and cause premature tire wear. Check your owner’s manual to learn how your TPMS works.