Sunoco Sunvis 1015 is a premium mineral based lubricant that is used in Hydraulic Systems. Sunvis is a line of Sunoco Lubricants that covers a variety of hydraulic applications. The "1000" series is a group of premium Anti-Wear (AW) hydraulic oils with outstanding oxidation resistance and a High Viscosity Index (HVI) which means it has great flow properties in extreme temperature conditions. 15 represents the thickness of the oil which is an International Standards Organization Viscosity Grade (ISO VG) 15.