1.Carry the smart key or place it inside the vehicle.
2.Make sure the parking brake is firmly applied
3.Place the shift lever in P (Park). Depress the brake pedal fully. You can also start the engine when the shift lever is in the N (Neutral) position.
4.Press the engine start/stop button while depressing the brake pedal.
5.Do not wait for the engine to warm up while the vehicle remains stationary. Start driving at moderate engine speeds. (Steep accelerating and decelerating should be avoided.)
WARNING - Unintended vehicle movement
Never leave the smart key in the vehicle with children or vehicle occupants who are unfamiliar with the vehicle operation. Pushing the engine start/stop button while the smart key is in the vehicle may result in unintended engine activation and/or unintended vehicle movement.

Do not press the ENGINE START/ STOP button for more than 10 seconds except when the stop lamp fuse is blown.
Kia Stinger (CK) 2018-2023 Owner's Manual: Engine coolant
The high-pressure cooling system has a reservoir filled with year round antifreeze coolant. The reservoir is filled at the factory. Check the antifreeze protection and coolant level at least once a year: at the beginning of the winter season, and before traveling to a colder climate. CAUTION - Radiator cap Never attempt to remove the radiator cap while the engine is operating or hot.Kia Stinger (CK) 2018-2023 Owner's Manual: Adaptive Front-Lighting System (AFS)
Specifications Specifications Content Value AFS Nominal Voltage DC 13.5V Max Voltage 16.5V Rated Voltage DC 9.5 - 16V Operating Temperature -22 to 167°F (-30 to 75°) Operating Current MAX.