1996 Pontiac Trans Sport Owner's Manual - Page 267

What Kind of Oil to Use Oils recommended for your vehicle can be identified by loolung for the "Starburst" symbol. This symbol indicates that the oil has been certified by the American Petroleum Institute (API). Do not use any oil which does not carry this Starburst symbol. If you change your own oil, be sureyou use oil that has the Starburst symbol on the front of the oil container. The engine oil fill cap is located just behind the engine oil dipstick. Just fill it enough to putthe level somewherein the proper operating range. Push the dipstick all the way back in when you're through. If you have your oil changed for you, be sure the oil put into your engineis American Petroleum Institute certified for gasoline engines. You should also use the proper viscosity oil for your vehicle, as shown in the followingchart: 6-11