1997 GMC Suburban Owner's Manual - Page 297

When to Add Oil If the oil is at orbelow the ADD mark, then you'll need to add at least one quart of oil. But you must use the right kind. This part explains what kind of oil to use. For crankcase capacity, see "Capacitiesand Specifications" in the Index. What Kind of Oil to Use Oils recommended for your vehicle can be identified by looking forthe "Starburst" symbol. Thissymbol 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 sure you use oil that has the Starburst symbol on the front of the oil container. NOTICE: Don't add too much oil. If your engine has so much oil that the oil level getsabove the upper mark that shows the properoperating range, your engine could be damaged. The engine oil fill cap on the "VORTEC" 5700 is located on the driver's side enginevalve cover. The engine oil fill cap on the "VORTEC" 7400 is located on the front of the engine, near the radiator. Be sure to fill it enough to put the level somewhere in 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 engine is American Petroleum Institute certified for gasoline engines. You should also usethe proper viscosity oil for your vehicle, as shown in the following chart: 6-15