Cold inflation pressure is the inflation pressure of tires before the car is driven and the tires warmed up. Recommended cold inflation pressure is displayed on the owner's manual and on the placard (or sticker) attached to the vehicle door edge, pillar, glovebox door or fuel filler flap. Drivers are encouraged to make sure their tires are adequately inflated, as suboptimal tire pressure can greatly reduce fuel economy, increase emissions, and can lead to premature failure of the tire. Excessive pressure, on the other hand, will lead to blowouts.
Tire pressure is measured in psi in the Imperial and customary systems, bar, which is deprecated but accepted for use with SI or the kilopascal (kPa), which is an SI unit.