Oil... how does it work? [split]

[TurboTravis]

@Vovchandr

I dont understand how a “thin, near water like” viscosity of 5 AT ANY TEMPERATURE, can be considered “thicker” than a honey type rating of 30 AT ANY TEMPERATURE by the same scale.

Scale doesn’t care what the temperature is. If it goes through the tube slow, it gets a high number, if it goes through the tube fast, it gets a low number.

A 5 went through the tube faster than 30, regardless of what temperature the fluid was set to before going through.

Do you agree with that?

No, I don’t.

An SAE 5 will go thru an orifice (tube) at zero degrees SLOWER than an SAE 30 will flow thru the same orifice at 210 degrees.

And if you want proof, put a quart of 5W30 outside overnight, to simulate it in your oil pan. Time how long it takes to pour out. This will simulate how fast a SAE 5/5W pours at cold temps, right? Right.

Do the same test after boiling the quart of oil for an hour. Because of the properties of a multigrade oil, the oil is an SAE 30 at the time of the aforementioned test.

I’ll bet you 1000 dollars right now that the boiled oil, which is an SAE 30, pours faster than the SAE 5 did at cold temps.

5W30-SAE 5@zero degrees, SAE 30@210 degrees.