| abstract |
Disclosed is a diesel engine lubricant capable of minimizing viscosity increases and which comprises a large amount of an oil having a lubricating viscosity and a small amount of a composition consisting of: A) the reaction product a succinic acylating agent (polyalkene substituent: Mn value at least 1200 and Mw / Mn ratio at least 1.5; at least 1.3 succinic groups per equivalent weight of the substituent group), and a compound containing at minus one -NH-; and B) a basic salt of alkaline earth or alkali metals of an acidic organic compound (metal ratio at least 2). TBN composition between 6 and 15. (A contribution: 0.5 to 1.5; B the balance; Mg contribution less than 30%). |