The lubrication battle was won 50 years ago.. They all lubricate just fine, even the Wally World special.. The difference between OEM oils and say Exxon and Texaco is the amount of carbon inhibitor. Those 5.00 a gal oils might have 6-8% where OEM oil will have 15-25%. Carbon inhibitors are the most expensive additive.
As fas burning the same name brand oil as your engine...it doesn't matter one bit.. Yamalube has been a synthetic/dino mix since they started making it. Yam is the only one that didn't need to come out with a special oil for the DFI engines. DFI engines produce lots more heat in the crankcase because they don't have gallons of cool fuel passing through the crankcases, it get injected directly into the combustion chambers. If to are running a Yam HPDI, Merc Optimax or a Evinrude DFI make sure you are burning one of the oil specifically designed for DFI's. Mercs Optimax oil and Evinrudes XD-50 along with Yamalube synthetic/dino mixes made to handle this heat.. If you are running a DFI then stick with DFI oils. If you are not then stick with OEM oils made for non DFI engines like Evinrude XD-30 or Merc Premium Plus. Buy in bulk with your own containers and buy the cheapest OEM oil for whatever your brand engine is.. Your Merc will run just fine on Rude oil or Yamalube.. Becareful with Merc oils. Merc's Premium is made for outboard 70hp and less. Merc's Premium Plus is made for 70hp and up.. Make sure you know what you are buying if it's being pumped out of a 55 gal drum.
Doesn't matter what you burn all engines need decarboned both 2 and 4 stroke. I recommend 50-75hrs on 2 strokes and 100hrs for 4 strokes. They are all burning the same fuel and 60% of the carbon comes from the fuel not the oil..
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