First oil change....AMSOIL 0w20 or 5w30.

[MrZappo]

LOL - too much speculation. Over-thinking. Non-engine builders making it complex.

Why thicker oil with some wear? As long as the oil pressure is there it's getting oil to where it should be and if the oil had a good rating under pressure (PSI rating among other things) there's no need to switch around. Pick one and use it regardless of miles.
I run the same oil be it the very first after I've built an engine or after I've got 40K on that same engine. Viscosity and pressure don't protect. The oil film does.
I run oils that have at least a 90 psi wear rating (as tested by an engineer) or 100psi+ is even better.
Viscosity is whatever.


Here's some quotes from an engineer and occasional racer -

• Oil flow is what carries heat away from internal engine components. Those engine components are DIRECTLY oil cooled, but only INdirectly water cooled. And better flowing thinner oil will keep critical engine components cooler because it carries heat away faster than slower flowing thicker oil can. This is especially important with plain main and rod bearings, since the flow of oil through the bearings is what cools them. If you run thicker oil than needed, you will drive up engine component temps.

Here are some comparison numbers from an 830 HP road race engine on the track:

15W50 oil = 80 psi = 265* oil sump temperature

5W20 oil = 65 psi = 240* oil sump temperature

(oil returns to the pan quicker, is cooler)


• Thinner oil flows quicker at cold start-up to begin lubricating critical engine components much more quickly than thicker oil can. Most engine wear takes place during cold start-up before oil flow can reach all the components (the longer an engine has been sitting, the more of a concern this becomes), and during warm-up while the oil is still thicker and not flowing as freely as it does during normal hot operating temperature. So, quicker flowing thinner oil will help reduce start-up and warm-up engine wear, which is actually reducing wear overall.

• The more free flowing thinner oil during cold start-up and warm-up, is also much less likely to cause the oil filter bypass to open up, compared to thicker oil. Of course if the bypass opened up, that would allow unfiltered oil to be pumped through the engine. The colder the ambient temperature, and the more rpm used when the engine is cold, the more important this becomes.

• Thinner oil also flows more freely when fully warmed-up to normal operating temperatures. And oil FLOW is lubrication, but oil pressure is NOT lubrication. Oil pressure is only a measurement of resistance to flow. Running thicker oil just to up the oil pressure is the wrong thing to do, because that only reduces oil flow/lubrication. Oil pressure in and of itself, is NOT what we are after.

Wow this is a relief ... So, either I'm not crazy which is great news ... Or were both crazy which honestly would be fine ...

Either way, I'm running my 0w20 and when my engine fails due to an internal lubrication issue Ill post back on this forum ... If forums still exist that far in the future ...

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[Riccochet]

The thing is, engines don't have tighter tolerances. Not in the aspect you assume. In fact, parts wear in to be relatively equal regardless of machining tolerances. The only reason to go with lighter oils is to squeeze every last fraction of a percent of fuel efficiency out of an engine design. Lighter oils, less flow and rotational resistance, higher efficiency.

We see it with every engine, from every manufacturer, throughout the years that engine is in service.

Remember, the manufacture doesn't care one bit if your engine lasts beyond the factory warranty period. In fact, it's in their best interests if it doesn't last much longer than the warranty period.

That being said. Modern oils with good additive packages do provide good protection. Heavier weight oils are only going to add to that protection.

 

[TrainMan]

I would stay with 0w20 or 5w20 when possible.

Btw I just found out there's 0w16 oil now! Probably 0w8 in a few years. Someday it will be like WD40 lol.

 

[Riccochet]

I would stay with 0w20 or 5w20 when possible.

Btw I just found out there's 0w16 oil now! Probably 0w8 in a few years. Someday it will be like WD40 lol.

There's already 0W5 on the market.

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