3.2.1 Typical values Gasoline have densities in the range 710 to 770 kg m-3 (68 to 52°API). The density of iso-octane, the benchmark hydrocarbon for performance, is 688 kg in4. Kinematic viscosities are usually in the range 0.4 to 1 cSt. For example ‘Shell V-Power Gasoline, currently the best selling premium gasoline in the US having a research octane number of 100, has a kinematic viscosity in the range 0.5 to 0.75 cSt at 40°C.
Fig: Viscosity of Aviation fuel and jet fuel
Conventional gasoline differs little in their kinematic viscosities and this quantity is not as important a factor in quality control as it is for some other petroleum products including lubricating oils. When `unconventional’ sources of fuel for spark ignition engines are being investigated the viscosity might well fall outside the range given above. For example with ‘catalytically upgraded’ pyrolysis oil from wood otherwise suitable for substituting for gasoline the viscosities were in the range 25 to 43 cSt. The value for iso-octane is 0.74 cSt.