Castrol cocktail - Your thoughts on this mix???

[Shannow]

Originally Posted By: CastroPenzoHavoMobil1
OP here...

I asked Castrol this question, and here is their response...


Here's a quote from correspondence that I've had with one of Castrol's formulating chemists...it's specifically about two 0Ws being a 0W when mixed.

Quote:
Hi

It's an interesting one. Certainly no guarantee of 0W being achieved but without knowing the oils it's difficult. Often PPDs are universal across an additive suppliers range. But if you had two oils with different DI, PPD and VII you might cause problems with used oil. Even if Ccs is ok for 0W

MRV can also run into problems when certain VMs are combined with other PPDs.

In my own car I will only top up with oils using the same additive system. (Diff grade can be ok if I'm desperate ) but I want to ensure no issues. (Eg silicates and sulphonate detergents mixing are not ideal either)

 

[JohnnyJohnson]

In Texas I'd use the Castrol Magnatec 5w-20 in the winter and save the Castrol Edge High Mileage 10w-40 for my summer oil.

 

[OVERKILL]

Originally Posted By: Artem
Oh come on, you can blend whatever the "F" you want. Make it 8w30, 7w30 or 9w30 if you want. Just because oil manufacturers all agreed to a standard 5w, 10, etc, doesn't mean you can't blend a 2w18 at home if you want. What a stupid thing to say in regards to blending viscosities.

Actually, it does mean that. The 0w, 5w, 10w ...etc Winter designations are based on limits, you don't have two sweet clues what the final W designation is for a blend because you aren't running CCS and MRV testing at home. You can guess that it might meet the requirements for a 5W, but you really don't KNOW.

The ranges applied to the 16, 20, 30, 40, 50, 60 grades are an entirely different set of numbers.

ExxonMobil and SOPUS didn't get together for drinks one day and decide to come up with this stuff, it was established by the SAE to standardize viscosity and later further improve the winter rating system, since pour point was determined to be unreliable.

I'm not sure what faux cred is supposed to be derived from conjuring up fictitious oil grades

Is there some underground group of people too cool for science and standards and this is your tag? Do you spray paint this stuff underneath bridges in case a chemist cycles by, he'll know the non-conformist "grade gangstas" have been there?

 

[Artem]

good one OVERKILL.

I doubt there's some underground fictitious oil grade crew blending Frenkenbrews in chop shops in the "hood". If there is, I certainly wasn't invited, so I'd be [censored] (not happy)

I mixed 4 quarts of Castrol Edge 5w20 + 1 quart of Edge 5w50. My calculator showed 5w26 as the result. It's not lab tested, I don't have the cSt @ 100C spec nor the resulting VI or anything else of serious note and IM PERFECTLY FINE WITH THAT. I've been sleeping like a baby with the 5w26 in the engine.