Gasoline fuel
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Gasoline is a mixture of nearly 300 different components, mainly hydrocarbons, which vary widely in physical and chemical properties. The properties of gasoline must be balanced to give satisfactory engine performance over a wide range of operating conditions including heat, altitude, and driving patterns. The more effectively liquid gasoline is changed into vapor, the more efficiently it burns in the engine.
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Gasoline fuel characteristics
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The most important characteristic of gasoline is its Research Octane Number (RON) or octane rating, which is a measure of how resistant gasoline is to premature detonation (knocking).
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Controlling fuel burn
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Detonation is a violent collision of flame fronts in the cylinder, caused by uncontrolled combustion. The sudden rise in pressure can cause a knocking sound.
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Stoichiometric ratio
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Stoichiometric ratio is the air-fuel ratio necessary for complete combustion.
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Air density
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The density of air is its mass per unit volume.
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Fuel supply system
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EFI is a circulation system. A pump draws fuel from the tank and sends it to solenoid-operated injection valves, where pressure is maintained by a fuel pressure regulator. Excess fuel flows back to the tank through a return line.
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Pressure & vacuum
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As air pressure is reduced, a vehicle has to reduce the amount of fuel delivered to the engine to maintain the correct air-fuel ratio.
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