PSA: Check your tire pressure cold, or your numbers will lie to you
I always checked my tires at the gas station after driving 20 minutes to get there, and my gauge kept showing 36 psi so I figured I was fine. A guy at the shop in Boise asked me when I had last checked them cold, and I had no answer. He explained that heat from driving can add 3 to 4 psi, so my real cold pressure was closer to 32 when my car wants 35. I bought a $12 gauge, started checking in my driveway at 7am before work, and sure enough I was underinflated for who knows how long. My mpg went from 29 to 31 over the next month, which adds up quick at 40 miles a day. Do you all check cold, or just top off at the station and call it good?