Table 2 lists the measured RON and MON of the five fuels used and the constants A, B and n calculated for the TPRF surrogates of the same RON and MON using the equations described in Section 2 and used in .
The model for TPRF in  was built using mixtures where RON and MON were both under 100 because the quantitative accuracy of RON/MON ratings above 100 is questionable.
Hence for fuels with nominal RON values much in excess of 100 such as ethanol, MTBE and toluene, the constants in Eq.4 were calculated using models based on TRF and using the Toluene Number, TN  since a TPRF model is not available.
[3.] Kalghatgi, G., Babiker, H., and Badra, J., "A Simple Method to Predict Knock Using Toluene, N-Heptane and Iso-Octane Blends (TPRF) as Gasoline Surrogates," SAE Int.
Centurion-Lara, "Gene organization and transcriptional analysis of the tprJ, tprI, tprG, and tprF
loci in Treponema pallidum strains Nichols and Sea 81-4," Journal of Bacteriology, vol.