Kia Optima: Recommended LubricantsTo help achieve proper engine and powertrain performance and durability, use only lubricants of the proper quality. The correct lubricants also help promote engine efficiency that results in improved fuel economy.
Engine oils labeled Energy Conserving Oil are now available. Along with other additional benefits, they contribute to fuel economy by reducing the amount of fuel necessary to overcome engine friction. Often, these improvements are difficult to measure in everyday driving, but in a year’s time, they can offer significant cost and energy savings.
These lubricants and fluids are recommended for use in your vehicle.

*1) Refer to the recommended SAE viscosity numbers on this page.
Recommended SAE Viscosity NumberInspection
1.
Turn ignition switch OFF.
2.
Disconnect the oil temperature
sensor connector.
3.
Measure resistance between sensor
signal terminal and sensor g ...
Inspection
Radiator Cap Testing
1.
Remove the radiator cap, wet
its seal with engine coolant, and then install it on a pressure tester.
2.
Apply a pressure of 93.16 ~ 122.58k ...
Removal
1.
Turn the ignition switch OFF and disconnect the battery
negative (-) cable.
2.
Lift the vehicle.
3.
Disconnect the canister cl ...