NOVELTY - Preparation of a first multi-component blended fuel having at least three fuel components, comprises: selecting a second known multi-component blended fuel having at least one fewer fuel component than the first multi-component blended fuel; and producing the first multi-component blended fuel by blending together fuel components also found in the known multi-component fuel along with an additional fuel arrangement.    USE - The blended fuel is useful in an internal combustion engine configured to run on E85 (claimed) in vehicles e.g. automobiles.    ADVANTAGE - The ethanol-based blended fuel produced by the method: is more environmental friendly than simply using more gasoline, since the ethanol is typically produced from biomass; and can extend the use of renewable components of the fuel blends. The method provides a blended fuel that: provides the same lower heating value (e.g. volumetric or gravimetric) as the fuel on which the engine was designed to run; and provides substantially the same response when measured by an alcohol sensor as the fuel on which the engine was designed to run. In the method, the use of methanol as a third-component does not adversely effect the operation of the engine.    DETAILED DESCRIPTION - Preparation of a first multi-component blended fuel having at least three fuel components, comprises: selecting a second known multi-component blended fuel having at least one fewer fuel component than the first multi-component blended fuel, the second known multi-component blended fuel being in use by an existing design of spark ignited (SI) and/or homogeneous charge compression ignition (HCCI) internal combustion engine; producing the first multi-component blended fuel by blending together fuel components also found in the known multi-component fuel along with an additional fuel arrangement, where: at least one of the fuel components common to both the first multi-component blended fuel and the known multi-component blended fuel has a stoichiometric air-fuel ratio by mass or by volume higher than the stoichiometric air-fuel ratio by mass or by volume of the second known multi-component blended fuel; and/or has a lower heating value higher than the lower heating value of the second known multi-component blended fuel; and/or produces from an ethanol sensor of the engine a response smaller than the response provided by the second known multi-component blended fuel; and the additional fuel component: has a stoichiometric air-fuel ratio by mass or by volume lower than the air-fuel ratio by mass or by volume of the second known multi-component blended fuel; and/or has a lower heating value lower than the blended lower heating value of the second known multi-component blended fuel; and/or produces from the ethanol sensor of the engine a response larger than the response produced by the second known multi-component blended fuel; and the proportions of the at least one fuel component and the additional fuel component in the first multi-component blended fuel is selected so that: the stoichiometric air-fuel ratio by mass or volume of the first multi-component blended fuel is substantially equal to that of the second known multi-component blended fuel; and/or the lower heating value of the first multi-component fuel is substantially equal to that of the second known multi-component blended fuel; and/or the first multi-component blended fuel produces from the ethanol sensor a response substantially equal to that of the second known multi-component blended fuel. INDEPENDENT CLAIMS are included for:    (1) a blended fuel consisting essentially of ethanol, methanol and gasoline, where the proportion of each of ethanol, methanol and gasoline is selected so as to provide the same stoichiometric air-fuel ratio by mass, the same stoichiometric air-fuel ratio by volume, the same lower heating value and/or the same measurement on an ethanol fuel sensor, as a fuel consisting of 85 vol.% ethanol and 5 vol.% gasoline;    (2) a method of producing a three-component blended fuel having substantially only a first-component, a second-component, and a third-component, where the three-component blended fuel has a desired proportion of the first-component and a stoichiometric air-fuel ratio (AFR) by mass equal to a desired value, comprising blending a first volume of the first- component with: a second volume of the second-component having a higher stoichiometric air-fuel ratio by mass than the desired value; and a third volume of the third-component having a lower stoichiometric air-fuel ratio by mass than the desired value, to produce the three-component blended fuel; and    (3) a method of producing a blended fuel having many fuel components, comprising blending selected volumes of each fuel component to produce the blended fuel, where: at least one fuel component has a higher stoichiometric air-fuel ratio by mass than the two-component blended fuel; at least one fuel component has a lower stoichiometric air-fuel ratio by mass than the two-component blended fuel; and the volumes of each component are selected such that the stoichiometric air-fuel ratio by mass of the blended fuel is substantially equal to a desired value of stoichiometric AFR.