Systems and methods are provided for the fractionation of lubricant feeds. A lubricant feed can be introduced into a vacuum distillation tower having a reduced pressure and a reduced or minimized water vapor partial pressure. The lubricant feed can be separated into a plurality of lubricant boiling range products. The can allow an overlap in boiling ranges of one or more products separated from the lubricant feed to be reduced or minimized.

A base stock having at least 90 wt. % saturates, an amount and distribution of aromatics, as determined by ultra violet (UV) spectroscopy, including an absorptivity between 280 and 320 nm of less than 0.015 l/gm-cm, a viscosity index (VI) from 80 to 120, and having a cycloparaffin performance ratio greater than 1.05 and a kinematic viscosity at 100° C. between 4 and 6 cSt. A base stock having at least 90 wt. % saturates, an amount and distribution of aromatics, as determined by UV spectroscopy, including an absorptivity between 280 and 320 nm of less than 0.020 l/gm-cm, a viscosity index (VI) from 80 to 120, and having a cycloparaffin performance ratio greater than 1.05 and a kinematic viscosity at 100° C. between 10 and 14 cSt. A lubricating oil having the base stock as a major component, and one or more additives as a minor component. Methods for improving oxidation performance and low temperature performance of formulated lubricant compositions through the compositionally advantaged base stock.

A base stock having at least 90 wt. % saturates, an amount and distribution of aromatics, as determined by ultra violet (UV) spectroscopy, including an absorptivity between 280 and 320 nm of less than 0.015 l/gm-cm, a viscosity index (VI) from 80 to 120, and having a cycloparaffin performance ratio greater than 1.05 and a kinematic viscosity at 100° C. between 4 and 6 cSt. A base stock having at least 90 wt. % saturates, an amount and distribution of aromatics, as determined by UV spectroscopy, including an absorptivity between 280 and 320 nm of less than 0.020 l/gm-cm, a viscosity index (VI) from 80 to 120, and having a cycloparaffin performance ratio greater than 1.05 and a kinematic viscosity at 100° C. between 10 and 14 cSt. A lubricating oil having the base stock as a major component, and one or more additives as a minor component. Methods for improving oxidation performance and low temperature performance of formulated lubricant compositions through the compositionally advantaged base stock.

A method of screening a hydrocarbon stream for potential toxicological hazards. The method involves providing a hydrocarbon stream; conducting 2-dimensional gas chromatography (2D-GC) analysis to quantify saturates and aromatic distribution in the hydrocarbon stream; identifying 2-8 ring aromatic distribution and weight percentage of 2-8 ring aromatic molecules in the hydrocarbon stream from the 2D-GC analysis; relating the weight percentage of 2-8 ring aromatic molecules in the hydrocarbon stream from the 2D-GC analysis to a mutagenicity index (MI), in which the MI is determined in accordance with ASTM Standard Method E 1687; and assessing a potential toxicological hazard of the hydrocarbon stream based on the weight percentage of 2-8 ring aromatic molecules in the hydrocarbon stream from the 2D-GC analysis and a MI threshold value. The 2-8 ring aromatic distribution preferably includes 3-6 ring aromatics, more preferably 3.5-5.5 ring aromatics. The 2-8 ring aromatic distribution includes mono alkylated and multi alkylated aromatic molecules.

A method of screening a hydrocarbon stream for potential toxicological hazards. The method involves providing a hydrocarbon stream; conducting 2-dimensional gas chromatography (2D-GC) analysis to quantify saturates and aromatic distribution in the hydrocarbon stream; identifying 2-8 ring aromatic distribution and weight percentage of 2-8 ring aromatic molecules in the hydrocarbon stream from the 2D-GC analysis; relating the weight percentage of 2-8 ring aromatic molecules in the hydrocarbon stream from the 2D-GC analysis to a mutagenicity index (MI), in which the MI is determined in accordance with ASTM Standard Method E 1687; and assessing a potential toxicological hazard of the hydrocarbon stream based on the weight percentage of 2-8 ring aromatic molecules in the hydrocarbon stream from the 2D-GC analysis and a MI threshold value. The 2-8 ring aromatic distribution preferably includes 3-6 ring aromatics, more preferably 3.5-5.5 ring aromatics. The 2-8 ring aromatic distribution includes mono alkylated and multi alkylated aromatic molecules.

A lubricating oil composition of the invention contains: a base oil; at least one of acid phosphate represented by formulae (1) and (2) below; and an antioxidant.

##STR00001##

In the above formulae: R.sup.1, R.sup.2 and R.sup.3 are alkyl groups; and at least one of R.sup.1 and R.sup.2 has 20 to 30 carbon atoms while R.sup.3 has 20 to 30 carbon atoms.

A lubricating oil composition of the invention contains: a base oil; at least one of acid phosphate represented by formulae (1) and (2) below; and an antioxidant.

##STR00001##

In the above formulae: R.sup.1, R.sup.2 and R.sup.3 are alkyl groups; and at least one of R.sup.1 and R.sup.2 has 20 to 30 carbon atoms while R.sup.3 has 20 to 30 carbon atoms.

A shock absorber oil composition of the invention includes a base oil: (A) at least one of phosphate, amine phosphate salt, phosphite and amine phosphite salt; (B) an amide compound; and (C) an N-substituted derivative of sarcosine.

A shock absorber oil composition of the invention includes a base oil: (A) at least one of phosphate, amine phosphate salt, phosphite and amine phosphite salt; (B) an amide compound; and (C) an N-substituted derivative of sarcosine.

The lubricating oil composition for a shock absorber of the present invention contains (A) a base oil composed of a mineral oil and/or a synthetic oil, (B) a tertiary amine represented by the following general formula (I), and (C) a zinc dithiophosphate represented by the following general formula (II): ##STR00001## wherein R.sup.1 and R.sup.2 each independently represent an aliphatic hydrocarbon group having from 1 to 5 carbon atoms, and R.sup.3 represents an aliphatic hydrocarbon group having from 12 to 24 carbon atoms in the general formula (I), ##STR00002## wherein R.sup.4 to R.sup.7 each independently represent one selected from an alkyl group and an alkenyl group each having 1 to 24 carbon atoms in the general formula (II).