Chevrolet 1995 Blazer Owner's Manual page 250

What Kind of Oil f o Use
Oils of the proper quality for your vehicle can be identified by looking for
the "Starburst" symbol. The "Starburst" symbol indicates that the oil has
been certified by the American Petroleum Institute (API), and is preferred
for use in your gasoline engine.
If you change your own oil, be sure you use oil that has the "Starburst"
symbol on the front of the oil container. If you have your oil changed for
you, be sure the oil put into your engine is American Petroleum Institute
certified for gasoline engines.
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