GM Lumina/Silhouette/Transport APVs 1990-1999 Repair Guide

Fuel and Oil Recommendations



The engine is designed to operate on unleaded gasoline ONLY and is essential for the proper operation of the emission control system. The use of unleaded fuel will reduce spark plug fouling, exhaust system corrosion and engine oil deterioration.

In most parts of the United States, fuel with an octane rating of 87 should be used; in high altitude areas, fuel with an octane rating as low as 85 may be used. Using fuels with a lower octane may decrease engine performance, increase emissions and engine wear.

In some areas, fuel consisting of a blend of alcohol may be used; this blend of gasoline and alcohol is known as gasohol. When using gasohol, never use blends exceeding 10% ethanol or 5% methanol.

The use of fuel with excessive amounts of alcohol may jeopardize the new car warranties.


See Figures 1 and 2

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Fig. Fig. 1: Look for the API oil identification label when choosing your engine oil

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Fig. Fig. 2: Recommended SAE engine oil viscosity grades for gasoline driven engines

Use only oil that has the API (American Petroleum Institute) designation SG or later.

Since the viscosity (thickness) of the engine oil affects fuel economy, it is recommended to select oil with reference to the outside temperature. For satisfactory lubrication, use lower viscosity oil for colder temperatures and higher viscosity oil for warmer temperatures.