7.5Wx30 Oil

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does 50/50 mix of 5Wx30 and 10Wx30 produce 7.5Wx30?

for example mixing Pennzoil platinum full synthetic 5Wx30 with 10Wx30
does it produce PP 7.5Wx30 (based on Pennzoil standards). I know some oils run thinner/thicker than others ...

Q2: is it bad to mix if you have left-overs?
 
Originally Posted By: OilUzer
does 50/50 mix of 5Wx30 and 10Wx30 produce 7.5Wx30?

for example mixing Pennzoil platinum full synthetic 5Wx30 with 10Wx30
does it produce PP 7.5Wx30 (based on Pennzoil standards). I know some oils run thinner/thicker than others ...

Q2: is it bad to mix if you have left-overs?


No, and no.
 
There is no such grade. It'll be either a 5w-30 or a 10w-30. Probably the latter.

Mixing is not optimal, but it isn't going to hurt anything.
 
Thank you!
what would the weight be then? it is not 10W and it is not 5W?
can you analyze fresh oil to figure out what weight it is? is there such a system like UOA for new oil. I am sure different companies may analyze each other's oil ...
 
Originally Posted By: OilUzer
Thank you!
what would the weight be then? it is not 10W and it is not 5W?
can you analyze fresh oil to figure out what weight it is? is there such a system like UOA for new oil. I am sure different companies may analyze each other's oil ...


The number in front of the W is not a grade/weight, it is simply a qualification of the oil's cold temperature performance.

The number after the W is the grade, and since both are 30's, the end result will be a 30.
 
When you mix oils with different W ratings it does not produce an oil that is an average of the oils mixed.

The problem is that the molecules of the oil with the higher W number will still turn into a wax at the same temperature they originally did before mixing.

In other words 10W oil molecules turn to wax at certain temperature, and those molecules will still turn to wax at the same temperature even if the oil is mixed with 5W or 0W. You will have molecules that turn into wax from the 10W mixed with molecules that will not turn into wax until they are much colder.

So no, mixing 10W with 5W does not yield 7.5W.

And no, mixing 10W with 0W does not yield 5W.

And no, mixing 5W with 0W does not yield 2.5W.
 
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Originally Posted By: JimPghPA


...The problem is that the molecules of the oil with the higher W number will still turn into a wax at the same temperature they originally did before mixing.

In other words 10W oil molecules turn to wax at certain temperature, and those molecules will still turn to wax at the same temperature even is the oil is mixed with 5W or 0W. You will have molecules that turn into wax from the 10W mixed with molecules that will not turn into wax until they are much colder...



How are you defining WAX?
 
Originally Posted By: OVERKILL
The number in front of the W is not a grade/weight, it is simply a qualification of the oil's cold temperature performance.

The number after the W is the grade, and since both are 30's, the end result will be a 30.

Thank you, for the 8,000,000th time.
 
Originally Posted By: MolaKule
Originally Posted By: JimPghPA


...The problem is that the molecules of the oil with the higher W number will still turn into a wax at the same temperature they originally did before mixing.

In other words 10W oil molecules turn to wax at certain temperature, and those molecules will still turn to wax at the same temperature even is the oil is mixed with 5W or 0W. You will have molecules that turn into wax from the 10W mixed with molecules that will not turn into wax until they are much colder...



How are you defining WAX?


Well, actually if you had pure 100% of those molecules they would become so thick that you could literally turn the container on its side or even upside down and they would not run.

The molecules do not flex or flow freely when they are cold enough to become wax.
 
Originally Posted By: JimPghPA
When you mix oils with different W ratings it does not produce an oil that is an average of the oils mixed.

The problem is that the molecules of the oil with the higher W number will still turn into a wax at the same temperature they originally did before mixing.

In other words 10W oil molecules turn to wax at certain temperature, and those molecules will still turn to wax at the same temperature even if the oil is mixed with 5W or 0W. You will have molecules that turn into wax from the 10W mixed with molecules that will not turn into wax until they are much colder.

So no, mixing 10W with 5W does not yield 7.5W.

And no, mixing 10W with 0W does not yield 5W.

And no, mixing 5W with 0W does not yield 2.5W.


Right...by the math it's 7.5, but the oil will likely perform in extreme cold as a 10w.
 
Originally Posted By: kschachn
Originally Posted By: OVERKILL
The number in front of the W is not a grade/weight, it is simply a qualification of the oil's cold temperature performance.

The number after the W is the grade, and since both are 30's, the end result will be a 30.

Thank you, for the 8,000,000th time.

OVERKILL, I don't think you're getting through to member kschachn. Maybe if you post it ONCE more he "MIGHT" get it then.
crackmeup2.gif
27.gif
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Originally Posted By: kschachn
Originally Posted By: OVERKILL
The number in front of the W is not a grade/weight, it is simply a qualification of the oil's cold temperature performance.

The number after the W is the grade, and since both are 30's, the end result will be a 30.

Thank you, for the 8,000,000th time.


LOL
grin.gif
 
I guess I was focusing too much on the math than the science of oil. seems like you can get a phd in oil and still not know much about it ... lol
having said that, I would have liked a 7.5Wx30. can we ask Pennzoil to make some?
 
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Originally Posted By: OilUzer
I guess I was focusing too much on the math than the science of oil. seems like you can get a phd in oil and still not know much about it ... lol
having said that, I would have liked a 7.5Wx30

What for?
 
I switch in summer to 10Wx30 and winter to 5Wx30. in my area we hardly go below 20F (maybe a few days max) and we hardly go over 95F (again not that often) but if I travel to other parts of state, we get into 100F in the summer ...
I am sure 5Wx30 or 10Wx30 is fine but I figured I do the math thing again and came up with 7.5W that way I don't have to buy both weights
smile.gif
 
Originally Posted By: OilUzer
I guess I was focusing too much on the math than the science of oil. seems like you can get a phd in oil and still not know much about it ... lol
having said that, I would have liked a 7.5Wx30


For this to make sense you need to understand that the numbers you are seeing do not represent a hard figure but rather a range.

I could post a copy of SAE J300 of that would help, but basically:

- Each grade is a range of viscosities as measured at 100C.

- Each "W" rating (Winter) is defined by limits established for the oil's ability to pump (MRV) and impact on cranking speed (CCS) at two separate temperatures, 5C apart. A W-rating for a given oil is then indicated by the lowest pair of tests that oil passes. This is generally dictated by the CCS limit, which has a much lower viscosity ceiling than MRV, which is also measured 5C lower.
 
Originally Posted By: OilUzer
I switch in summer to 10Wx30 and winter to 5Wx30. in my area we hardly go below 20F (maybe a few days max) and we hardly go over 95F (again not that often) but if I travel to other parts of state, we get into 100F in the summer ...
I am sure 5Wx30 or 10Wx30 is fine but I figured I do the math thing again and came up with 7.5W that way I don't have to buy both weights
smile.gif



Then just run 5w-30 year-round.
 
Originally Posted By: OVERKILL
Originally Posted By: OilUzer
I switch in summer to 10Wx30 and winter to 5Wx30. in my area we hardly go below 20F (maybe a few days max) and we hardly go over 95F (again not that often) but if I travel to other parts of state, we get into 100F in the summer ...
I am sure 5Wx30 or 10Wx30 is fine but I figured I do the math thing again and came up with 7.5W that way I don't have to buy both weights
smile.gif


Then just run 5w-30 year-round.

Exactly, and refrain from thinking the 5W (or a 0W for that matter) is "too thin" in summer because that's not how it works.

In fact, if the temperature hardly ever goes below 20F then 10W is fine too.
 
Thank you all. I am reading more about oil than I had planned to but it is fun ...
I was actually thinking of just getting 10Wx30 as suggested. I like PP so far. last time I used PP full synthetic 5Wx30 d1g2 and here we go again with my limited knowledge, I had also read that PP may run thinner than some other brands so I came to the conclusion that PP 10Wx30 maybe like 7.5wX30 which is what I was looking for ... LOL

edit:
I now know that logic does not work but sounds like 10Wx30 or 5Wx30 are both fine and I don't have to buy both.
 
Last edited:
Originally Posted By: OilUzer
Thank you all. I am reading more about oil than I had planned to but it is fun ...
I was actually thinking of just getting 10Wx30 as suggested. I like PP so far. last time I used PP full synthetic 5Wx30 d1g2 and here we go again with my limited knowledge, I had also read that PP may run thinner than some other brands so I came to the conclusion that PP 10Wx30 maybe like 7.5wX30 which is what I was looking for ... LOL


I still think you are confused on the topic here. If you want a heavier oil, run a Euro 0w-30/5w-30 or an HDEO 0w-30/5w-30/10w-30, all of which will be significantly heavier than your ILSAC GF-5 "Energy Conserving" xW-30's.

Castrol "GC" 0w-30 is significantly heavier than your 10w-30 at operating temperature, yet offers significantly better extreme low temperature performance. Once you've wrapped your head around that, you will likely better understand this subject.
 
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