The scaling analysis in SI E indicates that YSI is proportional to SP/S, where S is the moles of oxidizer required to stoichiometrically combust one mole of fuel . The figure in SI E shows that this relationship fits a wide range of pure hydrocarbons and mixtures where both YSI and SP have been measured . Based on the linear least-squares fit to the data in this figure, a derived smoke point (DSP) can be calculated from the measured YSIs with the equation: