[1st Method]

Start the engine and keep the engine running at idle for 2 minutes.
Step on the accelerator pedal and hold it steady at 4500 RPM with the shift lever in N position to warm up the engine until the temperature of the engine coolant reaches 80°C.
Keep the engine running at 2500~3000 RPM in the N position for 15 minutes.

Fig 1: Engine Running Timing Pattern

Courtesy of KIA MOTORS AMERICA, INC.