Adjust for seasonal temperature swings and do visual spot checks

Tire pressure rises and falls roughly 1 PSI for every 10 degrees F change in ambient temperature. A tire inflated to 35 PSI in summer can drop to 29 PSI by mid-winter, so check and adjust pressure at each major seasonal shift and whenever temperatures swing more than 20 degrees F over a few days.

Visual Cues to Watch For

• Bulging sidewalls: Suggest significant underinflation -- confirm with a gauge immediately
• Uneven tread wear: Inner-edge wear often signals chronic underinflation; outer-edge wear signals overinflation
• Cracking or dry rot: Indicates aging rubber, not a pressure issue, but warrants tire replacement

Tips

• Visual checks catch severe problems but cannot detect the 3-5 PSI losses that affect fuel economy and handling
• Set a calendar reminder to check pressure at the start of each season
• Nitrogen-filled tires lose pressure more slowly with temperature changes but still need periodic checks