Henry’s constants for hydrous ethanol, iso-octane and gasoline absorption in engine lubricants were determined using gas chromatography. Samples of synthetic SAE 5W30, synthetic SAE 5W40, semi-synthetic SAE 15W40, mineral SAE 15W40 and mineral SAE 25W60 oil were used in the experiments. For all lubricants tested, typical molecular weights were considered, ranging from 500 to 5000 kg/kmol. The results show that, for any lubricant, Henry’s constant for hydrous ethanol is about 2.2 times higher than that of gasoline, and about 4.3 times higher than that of iso-octane. Decreasing Henry’s constant was observed with increasing lubricant molecular weight, regardless of the fuel type.
- Henry’s constant
- Internal combustion engines