Summer heat does more than drain your battery—it changes your tire pressure. As temperatures rise, the air inside your tires expands. For every 10°F increase in outside temperature, tire pressure goes up by approximately 1 PSI. A tire set to the correct pressure on a cool morning can be running 4-6 PSI above spec by a hot afternoon.

Check Pressure When Tires Are "Cold"

The most accurate reading comes when tires are at ambient temperature—ideally early morning before the sun hits the pavement, or after the vehicle has been parked in the shade for at least three hours. Checking and adjusting pressure during the heat of the day will give you a falsely high reading, leading you to under-inflate and compromise safety.

Use the Right Reference Point

Do not use the maximum pressure number printed on the tire sidewall. That figure is the tire's upper limit, not the recommended operating pressure for your vehicle. Instead, always refer to the tire pressure placard inside the driver's door jamb—that's the number your EV was engineered to run on.

Why It Matters for EVs

Electric vehicles are heavier than conventional cars due to their battery packs, which puts extra load on tires. Under-inflated tires reduce efficiency and can cut driving range—with some estimates showing a 0.2% drop in mileage for every 1 PSI below the recommended level. In summer heat, proper pressure isn't just about safety—it's about getting the most out of every charge.