GUIDE – What you need to know about engine (boat) oil.

We present a simple guide to let you know everything you need to know about motor oil in the boat. Four questions and four answers to keep your inboard oil in check at all times, and activities to do before and after winterization. Oil type, filter operation, what are reasons to change oil. The inboard motor oil guide.

Boat Engine Oil FAQ

1. Does motor oil last forever?

No, because after a long period of use, even if it remains stationary, it loses its main characteristics. The peculiarities of the lubricant among other things are achieved by the addition of special additives that deteriorate the oil over time. These additives cause the oil to perform multiple functions within the engine: ensuring lubrication and limiting wear and tear on moving parts, preventing the formation of deposits and, last but not least, contributing to cooling.

2. Should the engine oil be changed during winterization?

It is always best to change the oil during stops, because even if you have used the engine very little, it begins an acidification process that-when the engine is stopped-can greatly reduce the life of the seals. It is therefore more convenient to winterize with new oil that will then be used during the following season.

• Read also: How to change engine oil filters on your boat

3. What is the oil filter used for?

The filter is intended to trap solid particles (silica and carbon) that the oil removes from inside the engine, which, if left unchecked, over time could compromise component reliability. To know the state of the oil, just touch it and feel the density/viscosity level; it should appear not too dark to the eye, otherwise it may be rich in carbon deposits.

4. How are the oils differentiated?

Oil is classified according to two characteristics: viscosity and quality. Viscosity indicates the fluidity of the lubricant and considers the ambient temperature where the oil is engaged. For example, an oil marked 15W40 is made to operate in temperatures ranging from -15° to +40°. Quality establishes the oil’s ability to perform lubrication and cooling tasks, and is regulated by international standards. It would be better not to top up the oil with one that has different characteristics from the one previously introduced, because you would risk losing the specific characteristics, unifying it into a low-quality one.

• Read also: How much does it cost to “service” your inboard