What is the normal range for fuel trim data?

[OMaci]

In practice, the short-term fuel trim in dynamic data streams is referred to as the adjustment value, with a normal correction range of ±10% and a correction limit of ±25%. The long-term fuel trim is called the learning value. At idle, the normal range for long-term fuel trim is ±4%, while under partial load, the normal range is ±8%. Additional information: Overview: The fuel trim value is a crucial indicator for ensuring engine performance and fuel efficiency. Significance: The ECU receives signals from the mass airflow sensor, air-fuel ratio, and oxygen sensors, adjusting fuel supply based on current load. Short-term trim values change constantly with load variations, while long-term trim generally does not intervene except during high power output, throttle opening exceeding limits, gear shifts, or sudden load changes. If the long-term trim value continuously fluctuates and the variation increases, it indicates a potential vehicle fault.