What is the Normal Air-Fuel Ratio for Cars?

[DonovanRose]

An air-fuel ratio of 14.7 is considered normal for cars. Below is relevant information: Air-Fuel Ratio: The air-fuel ratio refers to the ratio of air mass to fuel mass in the mixture, generally expressed as the grams of air consumed per gram of fuel burned. Theoretically, the complete combustion of 1kg of gasoline requires approximately 14.7kg of air. Exhaust Catalytic Efficiency: To achieve optimal exhaust catalytic efficiency, an oxygen sensor must be installed in the engine's exhaust pipe for closed-loop control. Its working principle involves the oxygen sensor measuring the oxygen concentration in the exhaust, converting it into an electrical signal, and sending it to the ECU. This ensures the engine's air-fuel ratio is maintained within a narrow, near-ideal range. Sensor Functioning Properly: If the air-fuel ratio is too high, although the conversion rates of CO and HC slightly improve, the conversion rate of NOx drops sharply to 20%. Therefore, maintaining the optimal air-fuel ratio is crucial, and the key is to ensure the oxygen sensor functions properly.