[BRUTAL64]

A very good way of explaining it Brian and Ben.

I learned this 30 years ago. When they first starting doing multi-weight oils, if you got it too hot it would turn to goo. So during the first few years, multi-weight oil had a bad rap.

[BRUTAL64]

Originally Posted by enkeivette

You're not allowed to roll your eyes until after I fail to understand your explanation.

Ok, point taken.

[enkeivette]

Originally Posted by Vettezuki

The oil is NOT becoming thicker in absolute terms with an increase in temperature, it's just thicker than it would have been if it was a straight 10 for example.

Ooooooooooooooooooooooooooooooooooooooooooooooooo.

This sentence right here did it.

So a 10w 30 is as thick as a 30 WOULD BE at 100c and as thick as a 10 would be at 20c.

So 10w 30 does get thinner, just not as thin as straight 10.



After all of this, I think I might switch to 0w 30. Why not? Thinner at start up and the same at operating temp as a 10w 30.

[BRIAN]

Originally Posted by BRUTAL64

I learned this 30 years ago.

I was -9 years old back then

[BRIAN]

Originally Posted by enkeivette

After all of this, I think I might switch to 0w 30. Why not? Thinner at start up and the same at operating temp as a 10w 30.

Just wait until you walk to the register with your 5 quarts of 0W-30, the looks you'll probably get are priceless

YouTube - Castrol oil commercial (think with your...

That oil isn't a "real" synthetic by the way I just like the commercial

[enkeivette]

So in reality, nothing is getting thicker. 10w 30 is just 10 weight oil with more resistance to thinning as it gets hotter than straight 10.

[Vettezuki]

Originally Posted by enkeivette

So in reality, nothing is getting thicker. 10w 30 is just 10 weight oil with more resistance to thinning as it gets hotter than straight 10.

That's one way to think about it The opposite way to think about it (and the original reason) is that it runs like a 30 weight but is thinner on start up.

The effect is achieved through a blend of oils and some pretty trick petro-chemistry.

[Vettezuki]

Originally Posted by enkeivette

. . . . After all of this, I think I might switch to 0w 30. Why not? Thinner at start up and the same at operating temp as a 10w 30.

Some, notably GM, do not recommend using an oil with such a spread. It's mixed from considerably different bases and apparently is more prone to thermal breakdown.

[Vettezuki]

Fun fact.

Formula 1 cars use an engine oil that is a straight weight and very nearly the viscosity of water. It must be pre-heated and circulated through the engine (as well as the coolant) in a detailed procedure before firing the engine. Failure to do so correctly results in a about a $200k engine rebuild.

[BRIAN]

Originally Posted by Vettezuki

Some, notably GM, do not recommend using an oil with such a spread. It's mixed from considerably different bases and apparently is more prone to thermal breakdown.

The 0W-30???