Does Auto Start-Stop Save Fuel?
3 Answers
Auto start-stop in cars does save fuel. When the auto start-stop function is activated, the engine is technically still operating, maintaining normal operating temperature, but the pulley stops and the rotational speed decreases. An engine is a machine capable of converting other forms of energy into mechanical energy, including internal combustion engines, reciprocating piston engines, external combustion engines, Stirling engines, steam engines, jet engines, and electric motors. The car engine is the power-generating device of a vehicle, serving as the heart of the car, determining its power, fuel efficiency, stability, and environmental friendliness. Depending on the power source, car engines can be categorized into diesel engines, gasoline engines, electric vehicle motors, and hybrid engines.
Having driven for over a decade, I find that the auto start-stop feature does save some fuel in urban traffic, especially when there are many traffic lights or severe congestion. During rush hour commutes in the past, the engine idling wasted fuel, but with the start-stop system shutting off the engine, fuel consumption drops instantly, and only a small amount is used upon restart. Data suggests an average fuel savings of 3% to 10%, and my personal experience shows about 5% savings in heavy traffic, reducing monthly refueling by one trip. However, the slight jerk upon restart can be noticeable, and sometimes the AC stops blowing air when the engine shuts off, making it uncomfortably warm. Additionally, frequent starts increase wear on the battery and starter, leading to earlier replacements and higher maintenance costs. But if you mostly drive on highways, it's better to turn it off for peace of mind. Overall, the fuel savings are real—just weigh the usage conditions wisely.
As an ordinary car owner who enjoys researching car features, I find the auto start-stop system quite practical for fuel saving. It automatically turns off the engine when stopping, such as at red lights, reducing idle fuel consumption. The system is efficient during restart, saving an average of 5% fuel. The effect is particularly noticeable in urban commuting and congested areas—for example, it can save more fuel in Beijing's traffic conditions. However, it's ineffective on highways where stops are infrequent. The slight vibration during restart might cause discomfort, affecting the driving experience. The start-stop function relies on battery health; in older cars with weaker batteries, restarts may be slower or unstable. I recommend using it more in city scenarios—proper usage can save dozens of yuan in monthly fuel costs, but don't forget to regularly check your vehicle's condition to ensure reliability.
