Understanding ActiveTune Trims INGL vs INST
Typically, when running in live correction mode, ActiveTune uses a blend of two correction methods to achieve the desired air fuel ratio.
INST ( instant correction ) this correction is the mathematical result of known air mass and known AFR. It assumes complete combustion and under perfect circumstances would be able to work all on it's own to achieve the desired target. This correction method introduces very little error but can't overcome inefficiencies in combustion which lead to missed target values for long periods of time.
INGL ( integral correction ) this correction acts relatively slowly to take up the slack when the instant correction alone is not able to hit the target. This correction is always changing by 1% per period determined by the AF delay map (ms). If the measured ratio is too lean it will increase by one and conversely if the measured value is too rich it will decrease by one. Because this correction is not relative to RPM or throttle it can introduce error when either is changed rapidly and therefore isn't always best to be used while dyno tuning.
TOT ( total correction ) this is simply the result of INST plus INGL clamped to within the total correction limit. This is the value that is actually applied to the current fuel mass when operating in live correction mode.