Abstract: An engine lubricant, especially an SAE OW engine lubricant is described. The engine lubricant has at least 15 wt % of at least one monoester and not more than 15 wt % of additives, wherein said at least one monoester, or mixture of said monoesters if more than one is present, has a kinematic viscosity at 100° C. of not more than 3.3, a viscosity index of at least 130 and a Noack evaporation loss of not more than 15 wt %. The monoester is preferably the reaction product of a monohydric alcohol and a monocarboxylic acid wherein said monohydric alcohol is at least one saturated branched-chain aliphatic monohydric alcohol having between 16 and 36, carbon atoms and wherein said monocarboxylic acid is at least one saturated straight-chain aliphatic monocarboxylic acid having between 5 and 10, preferably 5 and 7, carbon atoms. In preferred lubricants, the monoester, or mixtures of monoesters, have a pour point of not more than ?30° C. and a non-polarity index of at least 80.

Abstract: An engine lubricant, especially an SAE OW engine lubricant is described. The engine lubricant has at least 15 wt % of at least one monoester and not more than 15 wt % of additives, wherein said at least one monoester, or mixture of said monoesters if more than one is present, has a kinematic viscosity at 100° C. of not more than 3.3, a viscosity index of at least 130 and a Noack evaporation loss of not more than 15 wt %. The monoester is preferably the reaction product of a monohydric alcohol and a monocarboxylic acid wherein said monohydric alcohol is at least one saturated branched-chain aliphatic monohydric alcohol having between 16 and 36, carbon atoms and wherein said monocarboxylic acid is at least one saturated straight-chain aliphatic monocarboxylic acid having between 5 and 10, preferably 5 and 7, carbon atoms. In preferred lubricants, the monoester, or mixtures of monoesters, have a pour point of not more than ?30° C. and a non-polarity index of at least 80.

Abstract: Copolymers, desirably having a molecular weight of from 500 to 20000, of aminoesters or aminoamides of (meth)acrylic acid and (meth)acrylamides at a molar ratio of from 10:1 to 60:1, particularly from 12:1 to 50:1 and especially about 20:1, can act as gas hydrate inhibitors in water containing hydrocarbon gas streams. Desirably the aminoesters or aminoamides are N-alkyl-amino(esters or amides) in particular of the formula (I): H2C?CR1 C(O)XR2NR3R4 (I) where R1, R2, R3, R4 and X have defined meanings and the (meth)acrylamides are of the formula (II): H2C?CR6C(O)NR7R8 (II) where R6, R7 and R8 have defined meanings. Methods of treating gas water mixtures using the copolymers to inhibit gas hydrate formation are described.