Más que en el grado de viscosidad, creo que hay que fijarse en la clase y la categoría del aceite, que son las que finalmente indican qué tipo de aceite es adecuado para qué tipo de motor.
Copio de las "ACEA oil sequences 2016 Rev. 2" de 2018 (lo dejo en el original en inglés para que nadie pueda decirme eso de traduttore, traditore
):
Each set of Oil Sequences is designated for consumer use by a 2-part code comprising a letter to define the CLASS (e.g. C), and a number to define the CATEGORY (e.g. C1).
The CLASS indicates oil intended for a general type of engines–currently there are:
A/B = Gasoline and Light Duty Diesel Engines
C = Catalyst compatible oils for Gasoline and Light Duty Diesel Engines with Aftertreatment devices
E = Heavy Duty Diesel Engines
The CATEGORY indicates oils for different purposes or applications within that general class, related to some aspect or aspects of the performance level of the oil. Typical applications for each sequence are described below for guidance only. [...]
Actualmente sólo existen las siguientes categorías (omito las de la clase C porque, que yo sepa, los motores marinos no están provistos de catalizadores, y omito también las descripciones de las categorías que no vienen al caso, por tratarse de aceites para motores de prestaciones extremadamente altas):
A3/B3 Stable, stay-in-grade Engine Oil intended for use in Passenger Car & Light Duty Van Gasoline & Diesel Engines with extended drain intervals where specified by the Engine Manufacturer, and for severe operating conditions as defined by the Engine Manufacturer.
A3/B4 Stable, stay-in-grade Engine Oil intended for use at extended Drain Intervals in Passenger Car & Light Duty Van Gasoline & DI Diesel Engines, but also suitable for applications described under A3/B3.
A5/B5
E4 Stable, stay-in-grade oil providing excellent control of piston cleanliness, wear, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV and Euro V emission requirements and running under very severe conditions, e.g. significantly extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for engines without particulate filters, and for some EGR engines and some engines fitted with SCR NOx reduction systems. However, recommendations may differ between engine manufacturers so driver manuals and/or dealers shall be consulted if in doubt.
E6 Stable, stay-in-grade oil providing excellent control of piston cleanliness, wear, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV, Euro V and Euro VI emission requirements and running under very severe conditions, e.g. significantly extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for EGR engines, with or without particulate filters, and for engines fitted with SCR NOx reduction systems. E6 quality is strongly recommended for engines fitted with particulate filters and is designed for use in combination with low sulphur diesel fuel. However, recommendations may differ between engine manufacturers so driver manuals and/or dealers shall be consulted if in doubt.
E7
E9
Como se ve de la simple inspección de la figura, con un aceite A3/B3 cubrimos el 95% de los motores marinos, y con uno E4, el 5% restante. Y a partir de aquí, ajustamos el grado de viscosidad en función de la temperatura ambiente, pero considero que un aceite mineral SAE 15W40 cubre el 99% de las necesidades de los piratas aquí presentes.
Perdón por el rollo
Saludos y
