A dielectric fluid is provided comprising an oil and one or more compounds selected from the group consisting of phosphite compounds. It has been discovered that addition of one or more compounds selected from the group consisting of phosphite compounds to dielectric fluids comprising oil impart a stabilizing effect that reduces, inhibits or prevents formation of stray gases in the dielectric fluid during ordinary use.

The present disclosure relates to methods of lubricating an electric or a hybrid-electric transmission using a lubricant including a solvent system with a blend of one or more base oils with a branched diester and one or more poly(meth)acrylate copolymers, transmissions therefor, and lubricating compositions suitable for such applications that exhibit good lubricant properties, good electrical properties, and good cooling efficiency at the same time.

Provided is a lubricating oil composition for a transmission having excellent gear properties, clutch properties, cooling properties, and electric insulating properties. The lubricating oil composition for a transmission preparing by blending (A) a base oil, (B) a viscosity index improver having a mass average molecular weight of 10,000 to 50,000, and (C-1) a polyamide and/or (C-2) a polyol ester, the base oil (A) including (A-1) a synthetic oil having a kinematic viscosity at 100 C. of 1.0 to 10.0 mm.sup.2/s.

A grease composition includes a base oil, a thickener, and polymethyl methacrylate particles. The base oil is a poly--olefin. The polymethyl methacrylate particles have an average particle size of 2 m to 7 m. A content of the polymethyl methacrylate particles is 10% by mass to 20% by mass with respect to a total amount of the base oil and the thickener.

A grease composition includes a base oil, a thickener, and zirconium oxide particles. The base oil is a poly--olefin. The zirconium oxide particles have a median diameter D.sub.50 of 0.6 m to 4 m. A content of the zirconium oxide particles is 2% by mass to 15% by mass with respect to a total amount of the base oil and the thickener.

A lubricant formulation for an electric or hybrid vehicle includes a base oil, or a blend thereof, one or more additives, and a molybdenum amine complex, such as diisotridecylamine molybdate, are provided. Lubricant formulations can be characterized by one of: improving electric motor protection when a volatage is applied to an electrode in the presence of a formulation comprising the diisotridecylamine molybdate additive as compared to a fluid lacking the diisotridecylamine molybdate additive; maintaining the electrical resistance slope of a formulation comprising the diisotridecylamine molybdate additive as compared to a fluid lacking the diisotridecylamine molybdate additive; the formulation forming a protective film on copper surfaces; a change in color of the formulation indicating contact load, temperature, time, or viscosity change.

A hydrocarbon fluid is disclosed that has a pour point of at most 30 C., as measured by ASTM D5950, and that comprises at least 99 wt % of naphthenes and paraffins, based on the total weight of the hydrocarbon fluid, wherein the weight ratio of naphthenes to paraffins is at least 1, as measured by GC-MS, and wherein the paraffins consist essentially of isoparaffins, as determined by GC-FID. In addition, preferred uses of said hydrocarbon fluid are disclosed.

This disclosure relates to a lubricating oil (e.g., gear oil) for use in an electric or hybrid vehicle. The lubricating oil has a composition including one or more lubricating oil base stocks as a major component, and one or more lubricating oil additives, as a minor component. The one or more lubricating oil base stocks include at least one Group IV base oil, or at least one Group V base oil. The lubricating oil has a kinematic viscosity (KV.sub.100) from 1 cSt to 7 cSt at 100 C. as determined by ASTM D-445, and an electrical conductivity at room temperature of less than 15,000 pS/m as determined by ASTM D-2624. This disclosure also relates to methods for producing a lubricating oil for a transmission, gear train, gear set, gear box, or gears of an electric vehicle powertrain and methods for improving energy efficiency, while maintaining or improving wear control.

The disclosed technology relates to a lubricant composition for use in an automatic transmission of a hybrid electric vehicle, containing an oil of lubricating viscosity, at least one borate ester, and at least one phosphorus containing compound.

A transformer oil basestock is disclosed that includes at least 99 wt % of naphthenes and paraffins, based on the total weight of the transformer oil basestock, wherein the weight ratio of naphthenes to paraffins is at least 1, as measured by GC-MS, and wherein the paraffins consist essentially of isoparaffins, as determined by GC-FID. In addition, a transformer oil composition is disclosed that includes the transformer oil basestock, an anti-gassing agent and an antioxidant.