Unfortunately, there are also many myths surrounding gasoline and diesel fuels. Perhaps the most common myth involves gasoline octane. A significant portion of the population believes that the higher the gasoline octane, the better the gasoline. The thinking is that higher octane means more power and better fuel economy. The truth of the matter is that octane has no relationship to fuel quality, power, or economy.
Engine design determines what gasoline octane is required for a particular engine.
Therefore, it makes sense to use gasoline with the octane specified by the manufacturer. The ONLY reason to use a higher octane than recommended by the engine manfacturer is to stop engine knocking and the cause for the engine knocking should be determined quickly to prevent engine damage. Recently the Federal Government cited several major oil companies for misleading advertising with respect to gasoline. Virtually all of these ads implied that using premium grade gasoline in your car would give you more power and all round better performance. Several oil companies have had to refrain from making misleading statements and to promulgate information that you should use the grade of gasoline recommended in your owner's manual.