||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.
|Gasoline fuel characteristics
||There are several important characteristics of hydrocarbon based fuels: volatility, octane rating & energy content. 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). A range of fuel additives are used to change a fuel's performance characteristics.
|Controlling fuel burn
||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.
||Stoichiometric ratio is the air-fuel ratio necessary for complete combustion.
||The density of air is its mass per unit volume.
|Fuel supply system
||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.
|Pressure & vacuum
||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.