Too little neutralisation
With higher-sulphur fuel, combustion can create acidic conditions that require adequate neutralisation to protect liners and piston rings from corrosive wear.
Too much alkalinity can also be wrong
With very low-sulphur fuels, excessive alkaline reserve may contribute to deposits. Deposits can interfere with ring movement and lubrication.
Marine selection is application-specific
Engine type, fuel sulphur, BN requirement, feed rate and OEM service guidance must be considered together. Marine lubricant selection should not be reduced to SAE grade alone.
This article is general technical information and is not a substitute for the equipment OEM manual, lubricant manufacturer recommendation or site-specific engineering review.