A method for reducing fuel permeation through gasketed joints in an internal combustion engine (10) includes surface treating the gaskets in a halogenated medium before placing them into service. A low-cost elastomer such as acrylic, EPDM or HNBR, can be used for the gasket body. The halogenated medium may comprise either a liquid bath or a gaseous bath, into which the gasket is immersed. The halogenated medium bath is excited by heating to accelerate the halogenation process. A gasket treated according to this invention possesses a chemically altered exterior surface which substantially enhances its fuel permeability resistance at relatively low cost.
