When switching marine lubricants, it is important to have a good understanding of the oils in use to ensure there will be no problems when potentially combining lubricants.

Five different circumstances related to switching and mixing lubricants are explained below.

MIXING TWO MINERAL OILS

Changing between mineral oils is generally considered low risk due to the similarity of the chemical hydrocarbon structure of all base oils. We will advise minimising the amount of competitor oil that is mixed with ExxonMobil products.

MIXING MINERAL OILS WITH SYNTHETIC OILS

Mixing synthetic oils with mineral oils is not recommended because doing so dilutes or suppresses the superior properties of the synthetic oil. Some types of synthetic oil may have different structures to mineral oils, leading to compatibility problems.

MIXTURES OF DIFFERENT SYNTHETIC OILS

Synthetic oils of different base types should never be mixed, and we do not recommend mixing different brands of synthetic oil as this may compromise lubricant performance. In addition, the contaminants and impurities left in the used oil may cause instability when mixed with the new oil.

MIXTURES OF DIFFERENT GREASE PRODUCTS

As long as the soap components are compatible - such as having a lithium base - different brands of grease can combine well. However, if the soap base is not known, the grease should not be mixed.

MIXING DIFFERENT MARINE ENGINE LUBRICANTS

It is advisable to minimise mixing different oil brands. However it is recognised that this is not always possible. Base oils for marine engine oils usually have a chemically similar structure that typically does not lead to compatibility problems.

QUESTIONS?

Please contact the team if you have any questions or if you need some advice - lubricants@williams-shipping.co.uk, 023 8052 2163