Carbon Factor Cf

The fuel carbon factor Cf is the mass of CO2 produced per mass of fuel burned, the conversion that turns reported fuel consumption into the CO2 used for EEDI, EEXI, and CII. Standard tank-to-wake values are about 3.114 for residual and distillate fuel oil, 2.750 for LNG, and 1.375 for methanol, set out in the IMO guidelines and refined for life-cycle use in MEPC.391(81). Carbon-free fuels such as ammonia and hydrogen carry a tank-to-wake Cf of zero, which is why their accounting shifts to the wider well-to-wake basis.