Standard Test Method for Gum Content in Fuels by Jet Evaporation Aviation fuels, Existent gum, Motor gasoline, Solvent washed gum, Unwashed gum, Automotive engine fuels/oils, Aviation fuels, Evaporation residue, Evaporators/evaporation, Existent gum, Gasoline, Gum content (washed/unwashed), Jet evaporation, Unwashed gum content, Washed gum content