The fuel properties of biodiesel are strongly influenced by the proper­ties of the individual fatty esters as well as those of some minor com­ponents. Both moieties, the fatty acid and alcohol, have considerable influence on fuel properties such as CN, with relation to combustion and exhaust emissions, cold flow, oxidative stability, viscosity, and lubricity. It therefore appears reasonable to enrich (a) certain fatty ester(s) with desirable properties in the fuel, in order to improve the properties of the whole fuel. For example, from the presently available data, it appears that isopropyl esters have better fuel properties than methyl esters. The major disadvantage is the higher price of isopropanol in compari­son to methanol, besides modifications needed for the transesterifica­tion reaction. Similar observations likely hold for the fatty acid moiety. It may be possible in the future to improve the properties of biodiesel by means of genetic engineering of the parent oils, which could even­tually lead to a fuel enriched with (a) certain fatty acid(s), possibly oleic acid, that exhibits a combination of improved fuel properties.