What is the normal range for long-term fuel trim data?

[JuneFitz]

The long-term fuel trim range is ±10%, with a correction limit of ±25%. The long-term fuel trim value is referred to as the learned value. At idle, the normal range for long-term fuel trim is ±4%, and under partial load, the normal range is ±8%. The sign of the value indicates the correction direction of the current air-fuel mixture concentration: 1. Positive. This means enrichment correction, i.e., without correction, the current mixture would be lean, with an excess air coefficient greater than 1. 2. Negative. This indicates dilution correction, i.e., without correction, the current mixture would be rich, with an excess air coefficient less than 1. The long-term fuel trim value is referred to as the learned value. At idle, the normal range for long-term fuel trim is ±4%, and under partial load, the normal range is ±8%.