Use of a viscosity increasing component in a diesel fuel composition, for the purpose of improving the fuel economy of an engine into which the fuel composition is or is intended to be introduced, or of a vehicle powered by such an engine, wherein the viscosity increasing component is a viscosity index (VI) improving additive, wherein the VI improving additive comprises a linear block copolymer, which contains one or more monomer blocks selected from ethylene, propylene, butylene, butadiene, isoprene and styrene monomers and wherein the VI improving additive is used at a concentration of from 0.001% w/w to 0.05% w/w.

A method for stabilizing asphaltenes in petroleum feedstocks such as crude oil includes adding to the feedstock an effective amount of an additive containing at least one waste plastic. Suitable waste plastics include, but are not necessarily limited to, polyethylene, polyethylene terephthalate, polystyrene, polycarbonate, polyamide, and polyurethane, and combinations thereof. By “stabilizing” is meant keeping the asphaltenes in solution in the petroleum feedstocks.

Use of a viscosity increasing component in a diesel fuel composition, for the purpose of improving the fuel economy of an engine into which the fuel composition is or is intended to be introduced, or of a vehicle powered by such an engine, wherein the viscosity increasing component is a viscosity index (VI) improving additive, wherein the VI improving additive comprises a linear block copolymer, which contains one or more monomer blocks selected from ethylene, propylene, butylene, butadiene, isoprene and styrene monomers and wherein the VI improving additive is used at a concentration of from 0.001% w/w to 0.05% w/w.

A lubricant suitable for lubricating a two-stroke cycle engine which is fueled with a liquid fuel having a volatility less than that of gasoline comprises an oleaginous synthetic ester, a normally liquid solvent having a kinematic viscosity of less than about 5 or 2 mm.sup.2/s at 100 C. and a nitrogen-containing dispersant bearing a hydrocarbyl group of at least 26 carbon atoms and having a nitrogen content of at least 4 percent by weight. The nitrogen content of the lubricant is at least about 0.3 percent by weight.

The present invention relates to an additive for fuels such as diesel fuel and fuel oil, used respectively for diesel engines and boilers of various types, comprising a metal oxidation catalyst, an organic nitrate and a dispersing agent in suitable ratios, capable of improving combustion efficiency in such a way as to reduce the formation of particulate matter and consumption.

The present invention relates to an additive for fuels such as diesel fuel and fuel oil, used respectively for diesel engines and boilers of various types, comprising a metal oxidation catalyst, an organic nitrate and a dispersing agent in suitable ratios, capable of improving combustion efficiency in such a way as to reduce the formation of particulate matter and consumption.

A method of increasing the accuracy of the quantification of an analyte in a hydrocarbon, the analyte containing a marking compound, by obtaining a first sample containing (a) the hydrocarbon and (b) the marking compound, obtaining a homogeneity inducing material, contacting the homogeneity inducing material with an aliquot of the first sample in a volumetric ratio of greater than or equal to about 5:1 to produce a second sample, and determining an amount of the marking compound in the second sample using an analytical technique based on the marking material.

A method of increasing the accuracy of the quantification of an analyte in a hydrocarbon, the analyte containing a marking compound, by obtaining a first sample containing (a) the hydrocarbon and (b) the marking compound, obtaining a homogeneity inducing material, contacting the homogeneity inducing material with an aliquot of the first sample in a volumetric ratio of greater than or equal to about 5:1 to produce a second sample, and determining an amount of the marking compound in the second sample using an analytical technique based on the marking material.

A method for stabilizing asphaltenes in petroleum feedstocks such as crude oil includes adding to the feedstock an effective amount of an additive containing at least one waste plastic. Suitable waste plastics include, but are not necessarily limited to, polyethylene, polyethylene terephthalate, polystyrene, polycarbonate, polyamide, and polyurethane, and combinations thereof. By stabilizing is meant keeping the asphaltenes in solution in the petroleum feedstocks.