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

[Vovchandr]

@jdaniels

It’s all relative. It allows it to spin more easily than a standard, non multi-grade oil of a given viscosity rating AT THOSE EXACT TEMPS.

Again:

5 @ cold = 5W30 @ cold

I just don’t get where you see an inconsistency. The first number is what the VI additive allows it to flow like when cold. It only affects the cold temp rating. All it’s saying is WHEN I’M COLD, I SPIN EASIER THAN I WOULD WITHOUT AN ADDITIVE. This DOES NOT mean that the oil is THINNER @ 32* – just that it’s thinner than it would be without the additive @ 32*.

But overall the spinning will be harder then when it’s warm.

I understand what 5w30 means I explained it in one of the first posts, I have a problem with the fact that cold has an assignment of 5 instead of lets say 50 making it 50w30.

If an oil spun easier while cold it would make it 45w30. If it spun harder when cold, 55w30.

It would be consistent between both numbers. If SAE says the higher the number the thicker, why is the thick cold oil rated lower then when it’s warm?