The Fuel Composition Correction table is used to add or remove fuel where required. The amount of correction applied by this table scales with the Fuel Composition Scalar table. Eg, if the Composition Scalar table output is 50%, then 50% of the values of this table will be added to the fuel delivery amount. 

When in Flex Fuel mode, this table is a correction to the Flex Fuelling model the ECU is automatically calculating and therefore should always be 0% at the commencement of tuning.

It is common to see a minor correction around the low rpm and load areas where the injector may now be operating within its linear opening times once additional fuel is requested from the secondary fuel blend.