I don't want to get into a long discussion nor do I think I can change anyone's mind. This has been discussed before.
The facts are that yes no engine company makes their own oil filter, as no car company makes their either, as no car company makes their own tires, as in no car company makes their own batteries and on and on.
But one fact remains with any of these parts. The OEM of the car, boat engine or what ever has a set of specs for the tires, the oil filters for their engines and the battery as well. When they have that product put into their box it has the same specs as the original. They run the quality control.
To me that is important. That means the same filter material, the same material in the casing, the same relief spring for the bypass, the same sq inches of filter material. The same holds true for OEM tires on a car. GM has specs that they require in their tires that although XYZ builds the GM tire they also built the tire sold at the local store. Just because the tire is the correct size and brand does not mean it is the same as the OEM. You have to know how to read all of the numbers and letters on the side of a tire and then understand what they mean. OEM GM tires are designed for the particular car they are used on as in right down to the suspension tune. Tire companies built both under the same brand name except one may cost $20 more. The same goes for oil filters as batteries.
I believe oil filters, fuel filters, tire and batteries can all be make cheaper by just changing one or two specs, a little less element, a less quality bypass spring etc. How much it effects your engine is an unknown but that is an unknown I will not try to discover.
BTW most car dealers will tell you they love the Quick Lube joints. They get several engine over hauls a year due to them. Oil filters splitting, gasket failures, drain plugs cross threaded and the list goes on.
If you own a Yanmar 6LY series engine it has the red coolant in it as a lot of the newer Yanmars do. Now walk into any parts store and ask the attendant if they have coolant that will work in your engine. They will march you right over to the bottles that say "Mixes with all". Go ahead and use it. Yanmar has a replacement engine all ready and waiting.
I can tell you that in the seventies as a field rep I would go into my dealers and walk into the parts department to inspect fuel filters, oil filter and oil brands that the dealer was using. We had the authority to reject any warranty claims that were submitted with the engine using something other than a Porsche AG approved Mann or Mahle filter. That could be a $6 or $7k lesson that no one wanted to learn.
I buy and use OEM parts when ever I can get them. I find that the cost difference is worth the peace of mind. In the scheme of things saving a few hundred on a couple of parts just isn't worth it to me.
Your mileage may vary.
