A method comprising providing a first fluid, second fluid, and third fluid having a first kinematic viscosity and a first BN, a second kinematic viscosity and a second BN, and a third kinematic viscosity and a third BN respectively, obtaining data identifying (i) a target kinematic viscosity of a cylinder oil to be produced, (ii) a target BN of the cylinder oil to be produced, and (iii) the kinematic viscosity and the BN of each of the first, second, and third fluids. Based on at least the identified kinematic viscosity and BN, the method comprises determining a ratio of first, second, and third fluid to produce a cylinder oil having a kinematic viscosity corresponding to the target kinematic viscosity and/or a BN corresponding to the target BN, and blending the first, second, and third fluids in the determined ratio to produce the cylinder oil.

A lubricating oil additive composition including: (i) a Broensted acid salt of at least one first amide compound, the Broensted acid salt being a salt of the first amide compound and a Broensted acid, the first amide compound being a monoamide of at least one fatty acid (a1), and at least one amine compound (a2), the amine compound (a2) being an oligomer of at least one alkanolamine (a3) represented by the general formula (1):

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in the formula, n is 1 or 2; R.sup.1 is C1-4 linear chain alkylene or C3-10 branched chain alkylene, the C3-10 branched chain alkylene having a main chain, the main chain having a carbon number of 2; and when n is 2, a plurality of R.sup.1's may be the same, and may be different from each other.

A method and a device for induced formation of solid lubricant comprises providing (S10) of an article (10) to be processed. The article is exposed (S20) to a process fluid (34) comprising a solvent, impact media (20) and additives of solid-lubricant precursor substances. The solvent is a low-volatile high-flash solvent. The impact media are non-abrasive hard particles. The additives of solid-lubricant precursor substances are surface-reactive compounds serving as carriers of at least one of S, P, B and of at least one refractory metal. A velocity difference between surfaces (12) of the article and the impact media is created (S30). This causes impacts between the impact media and the article. Solid lubricant substances are formed (S40) on the surfaces by chemical reactions. The chemical reactions comprise the solid-lubricant precursor substances and are induced by the energy of the impacts. The chemical reactions take place at the surfaces of the article.

A method of producing a lube base oil mixture includes providing a waste lubricant-derived refined oil fraction derived from a waste lubricant containing a lube base oil of API Group I or II. The waste lubricant-derived refined oil fraction contains an ionic refined oil, a first regenerated base oil, or a combination thereof, dewaxing the waste lubricant-derived refined oil fraction to produce a second regenerated base oil, and blending the second regenerated base oil with a separate lube base oil to produce a lube base oil mixture of Group III or higher. The method has an economical advantage because low-quality waste lubricant is used as a feedstock for the production of higher quality lube base oils. In addition, the method is advantageous in an environmentally friendly aspect because waste lubricant is reused rather than being disposed of.