Base stocks and lubricant compositions containing same

A lubricating oil having a composition comprising a base stock as a major component;

• and one or more additives as a minor component;
• wherein the base stock has a kinematic viscosity at 100° C. between about 4 and about 6 cSt, and comprises:
• greater than or equal to about 90 wt. % saturates;
• an amount and distribution of aromatics, as determined by ultra violet (UV) spectroscopy, comprising an absorptivity between 280 and 320 nm of less than about 0.015 l/gm-cm;
• a viscosity index (VI) from 80 to 120, and having a cycloparaffin performance ratio greater than about 1.05.

A lubricating oil having a composition comprising a base stock as a major component;

• and one or more additives as a minor component;
• wherein the base stock has a kinematic viscosity at 100° C. between about 10 and about 14 cSt, and comprises:
• greater than or equal to about 90 wt. % saturates;
• an amount and distribution of aromatics, as determined by ultra violet (UV) spectroscopy, comprising an absorptivity between 280 and 320 nm of less than about 0.020 l/gm-cm;
• a viscosity index (VI) from 80 to 120, and having a cycloparaffin performance ratio greater than about 1.05.

A method for improving oxidation performance of a lubricating oil as measured by a rotating pressure vessel oxidation test (RPVOT) by ASTM D2272, said lubricating oil comprising a base stock having a kinematic viscosity at 100° C. between about 4 and about 6 cSt as a major component;

• and one or more additives as a minor component;
• wherein the base stock comprises:
• greater than or equal to about 90 wt. % saturates;
• an amount and distribution of aromatics, as determined by ultra violet (UV) spectroscopy, comprising an absorptivity between 280 and 320 nm of less than about 0.015 l/gm-cm;
• a viscosity index (VI) from 80 to 120, and has a cycloparaffin performance ratio greater than about 1.1;
• wherein said method comprises controlling the cycloparaffin performance ratio to achieve a ratio greater than about 1.05.

A method for improving oxidation performance of a lubricating oil as measured by a rotating pressure vessel oxidation test (RPVOT) by ASTM D2272, said lubricating oil comprising a base stock having a kinematic viscosity at 100° C. between about 10 and about 14 cSt as a major component;

• and one or more additives as a minor component;
• wherein the base stock comprises:
• greater than or equal to about 90 wt. % saturates;
• an amount and distribution of aromatics, as determined by ultra violet (UV) spectroscopy, comprising an absorptivity between 280 and 320 nm of less than about 0.020 l/gm-cm;
• a viscosity index (VI) from 80 to 120, and having a cycloparaffin performance ratio greater than about 1.3;
• wherein said method comprises controlling the cycloparaffin performance ratio to achieve a ratio greater than about 1.05.

A method for improving low temperature performance of a lubricating oil as measured by a mini-rotary viscometer (MRV) by ASTM D4684, said lubricating oil comprising a base stock having a kinematic viscosity at 100° C. between about 4 and about 6 cSt as a major component;

• and one or more additives as a minor component;
• wherein the base stock comprises:
• greater than or equal to about 90 wt. % saturates;
• an amount and distribution of aromatics, as determined by ultra violet (UV) spectroscopy, comprising an absorptivity between 280 and 320 nm of less than about 0.015 l/gm-cm:
• a viscosity index (VI) from 80 to 120, and has a cycloparaffin performance ratio greater than about 1.05;
• wherein said method comprises controlling the cycloparaffin performance ratio to achieve a ratio greater than about 1.1;
• controlling monocycloparaffinic species greater than about 44 wt. %, based on the total wt. % of all saturates and aromatics;
• and/or controlling iso-paraffinic species greater than about 21 wt. %, based on the total wt. % of all saturates and aromatics.

A method for improving low temperature performance of a lubricating oil as measured by a mini-rotary viscometer (MRV) by ASTM D4684, said lubricating oil comprising a base stock having a kinematic viscosity at 100° C. between about 10 and about 14 cSt as a major component;

• and one or more additives as a minor component;
• wherein the base stock comprises:
• greater than or equal to about 90 wt. % saturates;
• an amount and distribution of aromatics, as determined by ultra violet (UV) spectroscopy, comprising an absorptivity between 280 and 320 nm of less than about 0.020 l/gm-cm;
• a viscosity index (VI) from 80 to 120, and having a cycloparaffin performance ratio greater than about 1.3;
• wherein said method comprises controlling the cycloparaffin performance ratio to achieve a ratio greater than about 1.05;
• controlling monocycloparaffinic species greater than about 39 wt. %, based on the total wt. % of all saturates and aromatics;
• and/or controlling iso-paraffinic species greater than about 25 wt. %, based on the total wt. % of all saturates and aromatics.

A base stock blend comprising from 5 to 95 wt. % of a first base stock and from 5 to 95 wt. % of a second base stock, wherein the first base stock comprises:

• greater than or equal to about 90 wt. % saturates;
• an amount and distribution of aromatics, as determined by ultra violet (UV) spectroscopy, comprising an absorptivity between 280 and 320 nm of less than about 0.015 l/gm-cm;
• a viscosity index (VI) from 80 to 120, and has a cycloparaffin performance ratio greater than about 1.1 and a kinematic viscosity at 100° C. between about 4 and about 6 cSt;
• and wherein the second base stock comprises:
• greater than or equal to about 90 wt. % saturates;
• an amount and distribution of aromatics, as determined by ultra violet (UV) spectroscopy, comprising an absorptivity between 280 and 320 nm of less than about 0.020 l/gm-cm;
• a viscosity index (VI) from 80 to 120, and having a cycloparaffin performance ratio greater than about 1.05 and a kinematic viscosity at 100° C. between about 10 and about 14 cSt.