The lubricating oil composition of the present invention contains, together with a base oil, a viscosity index improver (A) including a comb-shaped polymer (A1), a detergent dispersant (B) including an alkali metal borate (B1) and an organometallic compound (B2) containing a metal atom selected from an alkali metal atom and an alkaline earth metal atom, and a friction modifier (C) including a molybdenum-containing friction modifier, with the total content of an alkali metal atom and an alkaline earth metal atom being 2,000 mass ppm or less. The lubricating oil composition of the present invention has excellent detergency, fuel saving properties, and LSPI-preventing properties.

Provided is a non-Newtonian engine oil lubricant composition with improved fuel efficiency and engine wear protection. The lubricant composition includes a major amount of a base oil including a Group II base stock and an optional Group V base stock, from 0.1 to 9.0 wt. % of at least one viscosity modifier and from 0.1 to 1.2 wt. % of at least one friction modifier. The non-Newtonian engine oil lubricant composition has a kinematic viscosity at 100 deg. C. of less than or equal to 10 cSt and an HTHS (ASTM D4683) of less than or equal to 2.2 cP at 150 C. Also provided are methods of using the lubricant composition in internal combustion engines and methods of making the lubricant composition.

A method for improving fuel efficiency while maintaining or improving deposit control, in an engine lubricated with a lubricating oil. The lubricating engine oil has a composition including from 20 to 85 wt % of a first lubricating oil base stock selected from the group consisting of a Group I base stock, a Group II base stock, a Group III base stock, a Group IV base stock, and combinations thereof; from 5 to 55 wt % of a second lubricating oil base stock comprising at least one ester based Group V base stock; from 5 to 20 wt % of at least one viscosity modifier, and one or more other lubricating oil additives. The lubricating engine oils are useful in internal combustion engines including direct injection, gasoline and diesel engines.

A lubricating composition comprises an oil-soluble poly(2-oxazoline) additive having the repeat unit:
N(COR.sup.1)CH.sub.2CH.sub.2 where the number of repeat units (n) is an integer between 4 and 1000; where the polymer carries an inorganic or organic nucleophilic polymerization terminating group t, and a linear, branched or cyclic hydrocarbyl polymerization initiator group (i); and where R.sup.1 comprises a single or a mixture of linear branched or cyclic hydrocarbyl groups having 1-100 carbon atoms, some or all having 12-100 carbon atoms, or of at least one macro-monomeric hydrocarbyl group with more than 50 carbon atoms provided that when the polymer is a homopolymer and R.sup.1 lacks any hetero atoms; (A) i has a molecular weight of less than 250 g/mol, and R.sup.1 has an average number of carbon atoms of 12 to 50; or (B) n is greater than 15. The polymer may provide the composition, in the form of a lubricant, with friction modifier, and with low impact on lubricant viscosity. The polymer may be a homopolymer, a block copolymer or a star polymer.

A lubricating composition comprises a major amount of an oil of lubricating viscosity and 0.01 to 25 percent by weight based on the weight of the composition, of a poly(2-oxazoline) polymer. The polymer has the repeat unit:

N(COR.sup.1)CH.sub.2CH.sub.2

wherein the number of repeat units (n) in the polymer is an integer between 4 and 1000, such as between 4 and 500. The polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit, the initiator group (i) being effective to initiate the polymerisation of linear, branched or cyclic hydrocarbyl moieties. At least 5% of the total number of the groups R.sup.1 in the polymer comprise alkenyl groups having between 15 and 20 carbon atoms.

A lubricating composition comprises a major amount of an oil of lubricating viscosity and 0.01 to 25 percent by weight based on the weight of the composition, of a poly(2-oxazoline) polymer. The polymer has the repeat unit:

N(COR.sup.1)CH.sub.2CH.sub.2

wherein the number of repeat units (n) in the polymer is an integer between 4 and 1000, such as between 4 and 500. The polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit, the initiator group (i) being effective to initiate the polymerisation of linear, branched or cyclic hydrocarbyl moieties. At least 5% of the total number of the groups R.sup.1 in the polymer comprise alkenyl groups having between 15 and 20 carbon atoms.

A lubricating composition comprises at least 50 percent by mass, based on the mass of the composition of an oil of lubricating viscosity and 0.01 to 25 percent by mass, based on the mass of the composition of an oil-soluble poly(2-oxazine) polymer. The polymer has the repeat unit:

##STR00001##

where the number (n) of repeat units is an integer between 4 and 500, such as between 4 and 400. The polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit, the initiator group (i) being effective to initiate the polymerisation of linear, branched or cyclic hydrocarbyl moieties. R.sup.1 comprises a single or a mixture of linear, branched or cyclic hydrocarbyl groups having 1-50 carbon atoms, some or all having 12-50 carbon atoms, or of at least one macro-monomeric hydrocarbyl group with more than 50 carbon atoms.

A lubricating composition comprises a major amount of an oil of lubricating viscosity and 0.01 to 25 percent by mass, based on the mass of the composition of an oil-soluble copolymer, The copolymer comprises units (a) and units (b):

N(COR.sup.1)CH.sub.2CH.sub.2(a)

N(COR.sup.2)CH.sub.2CH.sub.2CH.sub.2(b)

wherein the polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit (a) or (b), the initiator group (i) being effective to initiate the polymerisation of linear branched or cyclic hydrocarbyl moieties. R.sup.1 and R.sup.2 are the same or different and comprise a single or a mixture of linear, branched or cyclic hydrocarbyl groups having 1-50 carbon atoms, some or all having 12-50 carbon atoms, or of at least one macro-monomeric hydrocarbyl group with more than 50 carbon atoms.

The disclosure relates to viscosity improver concentrates comprising a bio-based liquid decarboxylated rosin acid as a solubilizer, and a viscosity index improver. The viscosity improver concentrate is used in lubricating oil compositions comprising base oil and optional additives. The decarboxylated rosin acid component has at least one or more of: one or more C?C groups, and 40-100 wt. % of tricyclic compounds having 18-20 carbon atoms; a sum of tricyclic compounds as aromatic and cycloaliphatic of 50-100 wt. %, based on total weight of the decarboxylated rosin acid; and an amount of cycloaliphatic compounds of 15-100 wt. %, based on total weight of the decarboxylated rosin acid. The viscosity improver concentrates comprising the solubilizer have comparable properties, including compatibility, kinematic viscosity, and viscosity index, to other commonly used fossil based solubilizers.

Relating to the field of lubricant, more particularly relates to lubricant for marine engine, notably for a two-stroke marine engine. More particularly, relates to a lubricant for a marine engine including at least one lubricant base oil and at least one fatty amine.