Oil system myths

yellow rose said

Not exactly. Pressure is resistance to flow.

And you are claiming the pan goes dry because oil is retained in the engine. I say there is no way any engine, even a low budget deal will retain all that oil.

So you are mixing two issues together that are not related.

One is a high volume pump making the pan go dry relative to a standard volume pump (who determines what “standard” is) and the engine retaining oil.

They are not the same and not related.

Whatever GPM the engine uses with a (for example and easy math) 10 GPM pump, it will use the same GPM with a 12.5 GPM pump, which is a 25% increase.

Click to expand...

But what about pressure? IMO you can't talk about flow (GPM) without referencing pressure. Lets use your example of a 10 GPM and 12.5 GPM pump. If both pumps open the relief valve at the same pressure (60 psi) and assuming the engine can only use, lets say 9 GPM at that pressure (60 psi), then yes the engine will use the same volume of oil.

Now lets take a pump capable of flowing the same 12.5 GPM but at 75 psi. The engines oil requirement is the same but you have changed the pressure. Will the pump move more oil? IMO yes, if the restriction in the engine is enough that it will reach max pressure set by the relief spring. The engine in this example only
requires 9 gpm at 60 psi and we have a pump capable of moving 12.5 gpm at 75
psi.

It's a complex problem and no two engines will be exactly the same.