What does ECO mean on an automatic transmission car?

[McRuby]

ECO in an automatic transmission car refers to the economic driving mode. ECO is an English abbreviation derived from Ecology (environmental protection), Conservation (energy saving), and Optimization (power). The Eco mode is further divided into active Eco driving mode and passive Eco driving mode. When the ECO indicator light on the dashboard illuminates, it indicates that the vehicle's economic mode has been activated. The Eco mode is categorized into active and passive types. The difference lies in the fact that the active type has a dedicated button, allowing the driver to choose whether to activate it. When the driver presses the Eco mode switch, the dashboard indicator light immediately turns on, and the vehicle automatically begins adjusting settings such as throttle opening, transmission shift logic, and air conditioning output power. The passive Eco mode does not have a dedicated button. When the dashboard ECO indicator light illuminates, it serves merely as a reminder function. The Eco system automatically evaluates your driving behavior; if your current driving operation achieves the optimal fuel supply, the dashboard will simultaneously display the ECO indicator light. Most cars employ the active Eco driving mode, meaning they have a dedicated switch button. During daily driving, we can generally activate the Eco mode. However, it is unnecessary to activate Eco mode when driving at speeds exceeding 120 km/h, during idle parking, in N/P gear, or in manual mode—especially when climbing hills. Doing so would not only fail to demonstrate the fuel-saving characteristics of Eco but also impact the vehicle's power performance. Additionally, the Eco mode typically becomes ineffective under the following circumstances: When the vehicle speed exceeds 120 kilometers per hour, the car prioritizes speed, causing the Eco mode to deactivate automatically. During idle parking or when in N/P gear or manual mode, the Eco mode may also become ineffective. When high torque output is required, such as when climbing a hill, the engine control unit prioritizes ensuring sufficient power to drive the vehicle, and the Eco mode will not function in such situations.