Tires are the only part touching the road. Pressure affects safety, comfort and fuel use.
Standard pressure is usually 2.3–2.5 bar, listed on the door frame, fuel cap or manual.
Over-inflation causes center wear, poor grip, longer braking distance and a rough ride.
Under-inflation causes side wear, higher fuel consumption, excessive heat and greater risk of blowouts.
Check pressure monthly, especially before long trips. Slow leaks from nails are common and hard to see.
Correct pressure makes tires last longer and the car safer.