The specific type of engine oil for a 1999 Chevy S10 depends on the engine it has. There were several engine options available that year. To know for sure, you need to check your owner's manual. The manual will specify the recommended oil type (conventional, synthetic blend, or full synthetic), viscosity (like 5W-30 or 10W-40), and API certification (like SM, SN, or SP).
However, common recommendations for 1999 Chevy S10 engines were often in the 5W-30 or 10W-30 range, depending on the climate. Always check your owner's manual for the definitive answer. Using the wrong oil can damage your engine.
