With winter here and a previous problem with gasoline in the oil, i've had my experiences with thin and thick oil. I was wondering what everyone's opinions were on the effect upon an engine. I assume that thin oil, causes a drop in oil pressure due to reduced resistance, and lack of lubrication when the engine gets hot. My big question is what a heavy oil could do. One might assume that running straight 30w or 40w to break in an engine would provide adequate oil pressure due to it's thickness but I was reading that this could also be it's downfall. From what I read, I gathered that the oil pickup screen can not effectively flow a heavy straight oil because of the surface tension of a heavy oil would make the screen's flow to be reduced. Anybody have an opinion on this? Sorry for the length.:SNSign:
Back to the basics.....oil.
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Lets assume that the pump would spin at a constant rate, at idle, 800 rpm. Wouldn't the pump process the same amount of oil (volume) regardless of the oil's thickness(unless my above statement holds true and thin oil would be able to flow a greater volume through the pump compared to thick oil )? I am not a mechanical engineer, so please correct me if i'm making myself out to be an idiot. I think the only variable would be pressure. And yes i'm questioning my own question.
these days oil is not dependant on weight for its film strength, especially with synthetic oils. lighter weight oils flow more easily, and thus get to where it needs to be sooner on cold starts. in cold weather you need a light weight oil, in hot weather you need a heavier weight oil. also which weight oil you use depends on the engine build as well. if you use tight clearances, then you need a lighter weight oil otherwise you are going to have bearing problems. as an engine wears, you can go to a heavier weight oil. if you start with larger bearing clearances, you should use a slightly heavier weight oil to allow for the larger clearances.
an oils lubricity is not determined by its weight. new cars these days use the lighter weight oils for lower pumping losses, and better fuel economy.
an oils lubricity is not determined by its weight. new cars these days use the lighter weight oils for lower pumping losses, and better fuel economy.
