An aviation gasoline composition comprising an impure iso-octane fraction, at least one xylene and at least one C.sub.4 or C.sub.5 alkane, wherein the impure iso-octane fraction in said composition is a fraction comprising at least 90 mol % iso-octane and having a final boiling point of at least 180 C. and is present in the composition in an amount in the range of from 30 to 80 vol. % based on the composition, the composition is substantially free of any lead compounds, the composition has a motor octane number of at least 94 and the composition has a final boiling point of at most 170 C. The composition of the present invention may be made by blending together an impure iso-octane fraction, xylene, at least one C.sub.4 or C.sub.5 alkane, optionally ethyl tertiary butyl ether, and optionally methylcyclopentadienyl manganese tricarbonyl and may he used in a spark ignition aviation engine, either alone or in combination with methanol or a methanol and water mixture.

The present disclosure provides base aviation gasoline formulations. In addition, the present disclosure provides formulations in which one or more additives can optionally be added to the base aviation gasoline formulation to produce a finished aviation gasoline formulation.

Described are preferred compositions for a motor fuel. Such motor fuels may be particularly well suited for use in the motor of an aircraft. In particular, compositions of the present disclosure may comprise 50-75 wt % isooctane/alkylates, 20-40 wt % ETBE, 0-3 wt % isobutane, and 0-5 wt % aromatics. The present disclosure describes a full spectrum of unleaded fuels with various motor octane (MON) values.

An aviation gasoline composition comprising an impure iso-octane fraction, at least one xylene and at least one C.sub.4 or C.sub.5 alkane, wherein the impure iso-octane fraction in said composition is a fraction comprising at least 90 mol % iso-octane and having a final boiling point of at least 180 C. and is present in the composition in an amount in the range of from 30 to 80 vol. % based on the composition, the composition is substantially free of any lead compounds, the composition has a motor octane number of at least 94 and the composition has a final boiling point of at most 170 C. The composition of the present invention may be made by blending together an impure iso-octane fraction, xylene, at least one C.sub.4 or C.sub.5 alkane, optionally ethyl tertiary butyl ether, and optionally methylcyclopentadienyl manganese tricarbonyl and may be used in a spark ignition aviation engine, either alone or in combination with methanol or a methanol and water mixture.

A diesel fuel additive includes a cetane number improver and an at least one organometallic combustion catalyst in solution and/or at least one metal-oxide combustion catalyst in suspension.

Aviation gasolines and additives may have manganese-containing anti-knock components. The scavengers herein mitigate the possible deleterious effects from using the manganese-containing anti-knock. The scavengers include molecules with a central atom of a Group 15 element other than nitrogen. Entities that are attached to the central atom are electron withdrawing entities including electron deficient atoms and electron deficient functional groups.

An additive has been prepared for blending with gasoline that facilitates a cylinder resident reaction, in high compression internal combustion engines (ICEs), to produce an increase in engine's mechanical energy output. A method of increasing mechanical efficiency of an internal combustion engine (ICE) comprising blending an amount of additive with gasoline to perform hydrolysis of olefin hydrocarbons, represented by octene (C8) into petroleum gas hydrocarbons, represented by butane (C4), wherein the additive facilitates cylinder-resident reaction, aided by a low concentration of organometallic catalyst, to utilize the elements of the water combustion product, to hydrolyze olefin hydrocarbons such as octene, resident in the gasoline, into petroleum gas hydrocarbons such as butane, and to increase the ICE's efficiency of utilization of the energy of the fuel.

A method for making a catalyst composition that includes a reduction catalyst mixture including a first reduction catalyst and a second reduction catalyst, wherein said first reduction catalyst comprises mixed vanadium oxides and phosphorus oxides, wherein said mixed vanadium and antimony oxides comprises V.sub.4Sb.sub.6O.sub.8, and wherein said second reduction catalyst comprises vanadium and antimony oxides; and an oxidation catalyst comprising ferrocene. The method includes selecting an organic petroleum distillate-soluble solvent that is effective to act as a reducing agent; introducing finely ground V.sub.2O.sub.5 and aqueous H.sub.3PO.sub.4 into said selected organic petroleum distillate-soluble solvent to make a first mixture; adding finely ground V/Sb oxide catalyst to said first mixture to make a second mixture; bringing the second mixture to a boil; cooling the second mixture; and adding the ferrocene or other organometallic Fe-source material to the cooled second mixture to make the catalyst composition.

Provided are oil-based fuel additive compositions that, when combusted with a fuel containing vanadium in a gas turbine, inhibit vanadium hot corrosion in the gas turbine. The oil-based fuel additive compositions include at least one rare earth element compound or alkaline earth element compound that retards vanadium corrosion resulting from combustion of vanadium rich fuel.

A process based on the combined use of yttrium and magnesium to inhibit vanadium corrosion of high temperature parts of thermal equipment. The combined use of yttrium and magnesium, applied in a variable yttrium/magnesium ratio, compared with conventional magnesium inhibition, may reduce emission of magnesium vanadate and minimize losses of performance due to fouling of the high temperature parts, including in the presence of alkali metals. Further, compared with inhibition based on yttrium alone, it may reduce the inhibition cost and reinforce the protection against combined vanadium pentoxide and sodium sulfate corrosion.