Chevrolet Spark Owner's Manual page 166

9–4 TECHNICAL INFORMATION
ENGINE OIL
API classification of engine oil
The International Lubricant Standardiza-
tion and Approval Committee (ILSAC)
and American Petroleum Institute (API)
classify engine oils according to their per-
formance quality. Always use oil rated API
SM 5W-30.
Engine
Select an oil viscosity based on the outside air temperature. Do not switch to
a different viscosity in the event of brief temperature fluctuations.