Kia Optima: Inflation PressuresAll tire pressures (including the spare) should be checked monthly when the tires are cold. “Cold Tires” means the vehicle has not been driven for at least three hours or driven less than one mile (1.2 km). Recommended pressures must be maintained for optimum vehicle handling, and minimum tire wear.

All specifications (sizes and pressures) can be found on a label attached to the front driver side door.
The correct tire pressure is 30 psi (210 kPa). The compact spare should be maintained at 60 psi (420 kPa).
WARNING - Tire Inflation
Over inflation or under inflation can reduce tire life, adversely affect vehicle handling, and lead to sudden tire failure. You could lose control and have a serious accident. Follow all the guidelines about proper tire maintenance.
Tire Care
Tire RotationSeat height (for driver’s seat)
Pull the front portion of the control switch up to raise or down to lower the
front part of the seat cushion. Pull the rear portion of the control switch up to
raise or down to lower the rear pa ...
Special Tools
Use special tools when they are required.
...
Removing and storing the spare
tire
Turn the tire hold-down wing bolt
counterclockwise.
Store the tire in the reverse order of
removal.
To prevent the spare tire and tools
from “rattling” while the vehicle is in
motion ...