"Detergent oils came into vogu
"Detergent oils came into vogue way back when full flow filtration started. The idea is that the detergents keep the impurities in suspension until the oil goes through the filter, where they are removed before the oil goes to do it's lubrication job.
Non-detergent oils are usually only used where there is no filtration, like in small air compressors, lawn mowers, etc.
Multi-vis oils were developed to provide a combination of good cold weather starting, plus protection at operating temps. Straight single grade oils are usually specced for engines that will never need to start in cold weather. I guess arguably boats fall into this category.
I am no expert on the 470, but for my money as long as it has an oil filter, I would think that you would be better off with a modern multi-vis 10W-30 or 10W-40 detergent motor oil. This would give you easier cold starts and better all round protection.
Does anyone out there know if there is something peculiar about the 470 engine that would make this not so?
Rod"