Kia Optima: Recommended lubricants and capacitiesTo 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.
These lubricants and fluids are recommended for use in your vehicle.

*1 Refer to the recommended SAE viscosity numbers on the next page.
*2 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.
*3 If the API service SM engine oil is not available in your country, you are
able to use API service SL.
Tires and wheels
Recommended SAE viscosity
numberDimensions Projected
1.
These are the dimensions
measured when the measurement points are projected from the vehicle's surface,
and are the reference dimensions used for used for body alterations ...
Seat belt restraint system
WARNING
For maximum restraint system protection, the seat belts must always be
used whenever the vehicle is moving.
Seat belts are most effective when seatbacks are in the upright position.
...
Fuel requirements
Your new Kia vehicle is designed to use only unleaded fuel having a pump octane
number ((R+M)/2) of 87 (Research Octane Number 91) or higher.
Your new vehicle is designed to obtain maximum performa ...