Aaaarrrggg!

[gfh77665]

I was just curious, thats all. Nothing more. I was just curious what the visc would be if I mixed one PYB straight 30wt. with 4 PYB 5w30's. I looked on the PZ website for respective cst's to plug into the visc. calculator. I couldn't find any. So just on a whim, I decided to call the PZ tech line.

I told the tech "I understand about viscosity, I know what the numbers mean. So, roughly, what visc would one PYB 30wt mixed with four PYB 5w30's be?"

She tell me, "well, umm, it would move towards being a 2.5-30 weight". I politely said: No, it would be more like a 10-30, since the straight 30 would thicken the mix somewhat".

Then the legalese came out: Whats the manufactures recommendation?...refer to your manual for correct weights...etc.

And SOPUS pays for this tech info?

 

[KrisZ]

I'm surprised you actually expected more. It's not like you're actually gonna talk to a tribologist.

 

[ARCOgraphite]

The chemist may have data. but the winter rating cant be extrapolated or interpolated. Only verified by measurement. What is your meaning of weight? That is outmoded terminology. IN SAE grading there (currently) exist no "in between" numbers. I could guess you might get a marginal fail 10winter multigrade if the oil is not an HDEO API service cat ( e.g: with certain detroit diesel approval) and its an API service SN SAE 30.
Advice wise, I wouldnt ask ofor help and then correct someone - just say thank you but I'll have to look into this further

 

[Kuato]

I certainly don't know the chemistry, but doing simple math...I'd agree with your 10w30 estimation.

 

[gfh77665]

Originally Posted By: ARCOgraphite

Advice wise, I wouldnt ask ofor help and then correct someone - just say thank you but I'll have to look into this further

I didn't ask for "advice". I asked for information, which is presumably what a product tech line is for. It was about their product information, not my vehicle(s).

I was extremely polite, but really I think she needed to know that blending a thicker visc does not make a lighter "2.5".

In ending I did politely thank her and hung up.

 

[zerosoma]

You would get jelly. Grape jelly.

 

[randomhero439]

1qt SAE 30, 4qt 5w30
KV100 10.8
VI 145
HTHS 3.1

PYB 10w30
KV100 10.5
VI 138
HTHS 3.1

As you can see the mix is thinner at all temps that PYB 10w30

 

[A_Harman]

Originally Posted By: randomhero439
1qt SAE 30, 4qt 5w30
KV100 10.8
VI 145
HTHS 3.1

PYB 10w30
KV100 10.5
VI 138
HTHS 3.1

As you can see the mix is thinner at all temps that PYB 10w30


It's interesting that the straight 30 doesn't wreck the VI of the 5w30. By definition, I believe the API classifies all oils below 120 VI to be monogrades. What is the VI of PYB 30?

 

[randomhero439]

Originally Posted By: A_Harman
Originally Posted By: randomhero439
1qt SAE 30, 4qt 5w30
KV100 10.8
VI 145
HTHS 3.1

PYB 10w30
KV100 10.5
VI 138
HTHS 3.1

As you can see the mix is thinner at all temps that PYB 10w30


It's interesting that the straight 30 doesn't wreck the VI of the 5w30. By definition, I believe the API classifies all oils below 120 VI to be monogrades. What is the VI of PYB 30?


I think it was 100

 

[gfh77665]

Originally Posted By: randomhero439
1qt SAE 30, 4qt 5w30
KV100 10.8
VI 145
HTHS 3.1

PYB 10w30
KV100 10.5
VI 138
HTHS 3.1

As you can see the mix is thinner at all temps that PYB 10w30


Thank you for that information , rh439.
If its no trouble, could you project the results of mixing 2 of 5, then 3 of 5 and 4 of 5? Thanks again!