- Joined
- Jul 8, 2022
- Messages
- 8
We recently purchased a 1996 Cobalt 232 with a 7.4L Merc. We houseboat at Lake Powell annually and wanted a big comfortable family cruiser to add to the mix. The boat is a time capsule and the maintenance records are extensive. She looks like she came off the factory floor yesterday.
As the title suggests, the engine is not a roller. I have looked through the forum and heard what sound to be valid arguments for and against the three main options for lube. Cost is not an issue on a boat which will have an oil change once a year, well within the 100 hour interval.
1) 25w40 Merc/Quicksilver
Pro-It’s recommended by the factory, it’s what has been used and it meets all the marine ratings.
Con-It is the factory fill for boats with catalytic systems, therefore does not have sufficient protection for a flat tappet engine. (I have not seen a recent VOA to either confirm or deny this claim)
2) SAE 40w
Pro- It is also recommended on the owners manual, the boat will only be ran in warm weather and the straight weight oil is more shear resistant.
Con- I have read that the HDEO Detroit rated oils would not be as well suited to the application due to low (zinc/phos). “Old tech, the 15w-40 will provide better protection.” No SAE 40w I can find has the marine specificatios.
3)15W40 HDEO
Pro-Many are available with sufficient zinc/phos (plenty of literature and voa’s to support this) , provides better protection on start up, is what Crusader Marin recommends (some of the longest lived engines on the water.
Con-multi weight oils are specifically not recommended in the manual.
What would you choose and why?
Thanks,
Garrison
As the title suggests, the engine is not a roller. I have looked through the forum and heard what sound to be valid arguments for and against the three main options for lube. Cost is not an issue on a boat which will have an oil change once a year, well within the 100 hour interval.
1) 25w40 Merc/Quicksilver
Pro-It’s recommended by the factory, it’s what has been used and it meets all the marine ratings.
Con-It is the factory fill for boats with catalytic systems, therefore does not have sufficient protection for a flat tappet engine. (I have not seen a recent VOA to either confirm or deny this claim)
2) SAE 40w
Pro- It is also recommended on the owners manual, the boat will only be ran in warm weather and the straight weight oil is more shear resistant.
Con- I have read that the HDEO Detroit rated oils would not be as well suited to the application due to low (zinc/phos). “Old tech, the 15w-40 will provide better protection.” No SAE 40w I can find has the marine specificatios.
3)15W40 HDEO
Pro-Many are available with sufficient zinc/phos (plenty of literature and voa’s to support this) , provides better protection on start up, is what Crusader Marin recommends (some of the longest lived engines on the water.
Con-multi weight oils are specifically not recommended in the manual.
What would you choose and why?
Thanks,
Garrison