Key takeaways
- Use the placard on your driver's door jamb, not the sidewall, for target PSI.
- Check tires cold — after sitting 3+ hours or driven less than a mile.
- Expect roughly 1 PSI change for every 10°F change in temperature.
- A TPMS warning below ~25% of target PSI is a safety issue, not a nuisance.
Where to find the right pressure
Open the driver's door and look at the placard on the jamb. That's the target PSI for the tires that came on your vehicle. The number molded into the sidewall of the tire itself is the maximum cold pressure — not the recommendation.
Cold vs hot readings
Check pressure cold. Driving warms the air inside the tire and inflates the reading by 3–5 PSI. Inflating to your target while the tires are hot leaves you underinflated by morning.
Why San Diego weather still matters
Coastal mornings in the 50s and afternoons in the 80s regularly swing tire pressure by 3–4 PSI. If your TPMS lights up on the first cold morning of the season, that's normal — top up to the door-jamb spec and it should stay off.
Frequently asked questions
Is a small TPMS warning ever safe to ignore?
Never for more than a quick trip to add air. TPMS activates when a tire drops roughly 25% below spec — pressure that low increases sidewall flex, heat, and blowout risk.
What if my TPMS won't reset after I refill?
Most systems reset after driving a short distance above ~20 mph. If not, a sensor may be failing. Our roadside team can help diagnose during any service call.