The lubricity of ethanol-gasoline fuel blends

in this work the lubricity of several ethanol (hydrated or anhydrous) / gasoline fuel blends was measured by using a conventional hfrr tester. tests were carried out at 25°c with no water vapour pressure control, according to the astm d6079 standard. according to the results the range of variation of the mean wear scar diameter was small among tested fuels in the range e-20 to e-85, indicating that the addition of ethanol, anhydrous or hydrated, did not impact significantly blend lubricity. the addition of hydrated ethanol (96% v/v) slightly improved blend lubricity in comparison with the addition of anhydrous ethanol. the higher mean wear scar diameters, lower fluid film traces and higher friction coefficients obtained for all tested fuels, in comparison with the typical values for diesel fuels, indicate the necessity of using lubricity additives when gasoline or ethanol / gasoline blends are used in new engine technologies requiring higher pressures in the fuel injection system.