INBOARD MARINE OIL 4T 25W40 15L BOX 3X5L

Function and technical context

This four-stroke marine lubricant with 25W40 viscosity is specifically formulated for inboard engines for nautical use, where working conditions differ significantly from terrestrial environments: presence of saline humidity, intense thermal cycles and long hours of operation at constant speed. It acts in the engine lubrication system, creating a protective film on the crankshaft, camshaft, pistons and bearings to minimize metal-to-metal wear. Its marine formulation contemplates resistance to emulsification with the water that inevitably comes into contact with the engine in marine environments, something that a conventional automotive oil does not guarantee. Premature oil degradation or the use of an inappropriate lubricant can lead to accelerated wear of internal engine components, loss of compression, overheating and, in extreme cases, engine seizure.

When to replace this oil?

The most common symptoms that indicate that the inboard engine oil needs to be renewed include a dark or blackish color on the dipstick, foaming or milky appearance (a sign of water contamination), a burning smell, and a noticeable increase in lubricant consumption between changes. For inboard engines for recreational use, the recommended change interval is 100 hours of operation or at the beginning of each season, whichever comes first, always coinciding with the oil filter check. Performing a preventive oil change at the beginning of the nautical season is the practice most recommended by specialized workshops to avoid costly out-of-port engine block repairs.

Equivalent manufacturer part numbers