The invention comprises synergistic compositions of at least two metal carboxylates as corrosion inhibitors based on polycarboxylate anions and a variety of different cations. The inhibitors are designed to be added to film forming or other compositions to reduce the corrosion of the metal substrate on which the synergistic compositions are applied.

A method for improving wear control of a steel surface lubricated with a lubricating oil through the generation of thick tribofilms. The method includes: (i) using as the lubricating oil a formulated oil, the formulated oil having a composition comprising at least one lubricating oil base stock as a major component; and at least one lubricating oil additive, as a minor component; and (ii) forming a tribofilm on the steel surface. In time-step tribofilm formation measurements of the lubricating oil by a mini-traction machine (MTM) at constant slide-to-roll ratio (SRR), the saturation traction coefficient (f.sub.s), which correlates to tribofilm thickness on the steel surface, is greater than about 0.11. In the method of this disclosure, elongation of timing chain due to wear of chain link pins is less than about 0.07%, as determined by Ford Chain Wear (FCW) test conducted in accordance with ILSAC GF-6 specification. The lubricating oils are useful in internal combustion engines.

A method for improving wear control of a steel surface lubricated with a lubricating oil through the generation of thick tribofilms. The method includes: (i) using as the lubricating oil a formulated oil, the formulated oil having a composition comprising at least one lubricating oil base stock as a major component; and at least one lubricating oil additive, as a minor component; and (ii) forming a tribofilm on the steel surface. In time-step tribofilm formation measurements of the lubricating oil by a mini-traction machine (MTM) at constant slide-to-roll ratio (SRR), the saturation traction coefficient (f.sub.s), which correlates to tribofilm thickness on the steel surface, is greater than about 0.11. In the method of this disclosure, elongation of timing chain due to wear of chain link pins is less than about 0.07%, as determined by Ford Chain Wear (FCW) test conducted in accordance with ILSAC GF-6 specification. The lubricating oils are useful in internal combustion engines.

A method for improving wear control, while maintaining or improving deposit control and cleanliness, in an engine or other mechanical component lubricated with a lubricating oil by using as the lubricating oil a formulated oil. The formulated oil has a composition including a lubricating oil base stock as a major component, and specific combinations of low soap detergents, dispersants, and/or mixtures thereof, as a minor component. The low soap detergents include alkaline earth metal salicylates, alkaline earth metal sulfonates, or mixtures thereof, all having the same or different total base number (TBN). The total amount of soap delivered by the low soap detergent is less than 0.60 weight percent of the lubricating oil. The dispersants include borated and/or non-borated polyisobutylene succinimide (PIMA) having a basic nitrogen content of 1% or greater. The lubricating oils are useful in internal combustion engines.

A method for improving wear control of a steel surface lubricated with a lubricating oil through the generation of fast-forming tribofilms. The method includes: (i) using as the lubricating oil a formulated oil, the formulated oil having a composition comprising at least one lubricating oil base stock as a major component, and at least one detergent, as a minor component; and (ii) forming a tribofilm on the steel surface. The time for the tribofilm to reach 95% of its saturation coverage (t.sub.95,sat) on the steel surface is less than about 50 minutes, as determined by a high frequency reciprocating rig (HFRR) in accordance with a modified version of ASTM D6079. A lubricating oil including an ester base stock, an alkylated naphthalene base stock, or mixtures thereof, as a major component; and at least one detergent including an alkaline earth metal salicylate, an alkaline earth metal sulfonate, or mixtures thereof, as a minor component.

The present invention relates to novel uses of corrosion inhibitors in fuels and lubricants.

The present invention relates to novel uses of corrosion inhibitors in fuels and lubricants.

The invention is directed to a method for reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine by supplying to the sump a lubricant composition which contains an oil of lubricating viscosity and an oil soluble metal compound, wherein the metal of the oil soluble metal compound may be a group (IV) metal, which may be titanium or zirconium.

The invention is directed to a method for reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine by supplying to the sump a lubricant composition which contains an oil of lubricating viscosity and an oil soluble metal compound, wherein the metal of the oil soluble metal compound may be a group (IV) metal, which may be titanium or zirconium.

A method for improving deposit control and cleanliness performance in an engine lubricated with a lubricating oil by using as the lubricating oil a formulated oil. The formulated oil comprises a lubricating oil base stock as a major component, and a mixture of (i) at least one dispersant, and (ii) at least one viscosity modifier, as minor components. The at least one dispersant and the at least one viscosity modifier are present in an amount sufficient to have a critical dispersant thickening ratio of greater than 0.33. The critical dispersant thickening ratio is determined in accordance with the formula:

[00001]$\frac{{\left[G_n\right]}^{*}.Math.\mathrm{dV}.Math.\text{/}.Math.d\left[G_n\right]}{{\left[B_m\right]}^{*}.Math.\mathrm{dV}.Math.\text{/}.Math.d\left[B_m\right]}$

wherein [G.sub.n] is the weight percent of each of n dispersants in the formulated oil, [B.sub.m] is the weight percent of each of m viscosity modifiers in the formulated oil, dV/d[G.sub.n] is the kinematic viscosity (Kv.sub.100) increase of the lubricating oil per the weight percent of each of n dispersants in the formulated oil, and dV/d[B.sub.m] is the kinematic viscosity (Kv.sub.100) increase of the lubricating oil per the weight percent of each of m viscosity modifiers in the formulated oil.