The recommended tire pressure for a car can vary depending on the vehicle, tire size, and load requirements. However, most passenger cars psi requirement will be between 30 to 35 psi. To find the exact recommended tire pressure for your vehicle, you can check the manufacturer-recommended tire pressures on a sticker affixed to the driver-side door jamb, which is the body pillar the door locks into. It could also be on the rear edge of the door itself, in the glove box or on the inside of the fuel-filler door. You can also find it in the owner’s manual. It is important to note that the pressures listed are for the tire size that originally came on the vehicle, which is also listed on the sticker. If different-sized wheels and tires have been installed, the listed pressures won’t necessarily be optimal. Additionally, tire pressure fluctuates by 1 pound per square inch for every change in temperature of 10 degrees, as air in the tire expands when it gets hotter (raising the pressure) and contracts when it gets colder (lowering the pressure) . Therefore, it is recommended to check tire pressure when the tires are cold, before driving the car that day.