Abstract
The paper presents the results of research into the biostability of M-10 base oil samples with addition of protective additives for various purposes which are a part of the earlier composition of M-14В2 lubricating oil developed by us. It was established that despite the different nature of these additives (alkyl phenolates, dithiophosphates, sulfonates), all these samples are affected by microorganisms. It found that the introduction of 0,25% α-phenyl-β-nitroethene into the composition of these samples provides their long-term protection from microbiological damage. Based on the results obtained, a new biostable lubricating oil composition for marine, locomotive and stationary diesel engines was developed which does not lose its performance properties for a long time.