NOVELTY - Unleaded aviation fuel composition having a motor octane number (MON) of at least 99.6, sulfur content of less than 0.05 wt.%, carbon, hydrogen and nitrogen (CHN) content of at least 98 wt.%, less than 2 wt.% of oxygen content, an adjusted heat of combustion of at least 43.5 MJ/kg, a vapor pressure of 38-49 kPa and freezing point of less than -58 degrees C, comprises a blend comprising: 35-55 vol.% toluene; 4-10 vol.% aromatic amine component; 15-40 vol.% at least one alkylate or alkylate blend; and at least 14 vol.% isopentane.    USE - The unleaded aviation fuel composition is useful for operating aircraft engine such as a spark ignition piston-driven engine.    ADVANTAGE - The unleaded aviation fuel composition: has MON of at least 99.6, sulfur content of less than 0.05 wt.%, CHN content of at least 98 wt.%, oxygen content of less than 2 wt.%, an adjusted heat of combustion of at least 43.5 MJ/kg, a vapor pressure of 38-49 kPa and freezing point of less than -58 degrees C (claimed); has high octane and aromatics content; and starts the engine easily.    DETAILED DESCRIPTION - Unleaded aviation fuel composition having a motor octane number (MON) of at least 99.6, sulfur content of less than 0.05 wt.%, carbon, hydrogen and nitrogen (CHN) content of at least 98 wt.%, less than 2 wt.% of oxygen content, an adjusted heat of combustion of at least 43.5 MJ/kg, a vapor pressure of 38-49 kPa and freezing point of less than -58 degrees C, comprises a blend comprising: 35-55 vol.% toluene having a MON of at least 107; 4-10 vol.% aromatic amine component that contains at least 2 vol.% toluidine based on the fuel composition; 15-40 vol.% at least one alkylate or alkylate blend having an initial boiling range of 32-60 degrees C and a final boiling range of 105-140 degrees C, T40 of less than 99 degrees C, T50 of less than 100 degrees C and T90 of less than 110 degrees C, and comprising isoparaffins having 4-9 carbon atoms, 3-20 vol.% 5C isoparaffins, 2-15 vol.% 7C isoparaffins and 60-90 vol.% 8C isoparaffins, based on the alkylate or alkylate blend, and less than 1 vol.% isoparaffins having more than 10C based on the alkylate or alkylate blend; and at least 14 vol.% isopentane to reach a vapor pressure of 38-49 kPa. The combined amount of toluene and aromatic amine component in the fuel composition is at least 40 vol.%. The fuel composition contains less than 1 vol.% 8C aromatics.