mixing viscosity oils

[Whipcitywrencher]

Hi All, New to Forum,

If you took 2.5 Quarts of 5w30 and mixed it with 2.5 quarts of 0w40 would you end up with 2.5w35 like wise could you mix 0w30 with 0w40 equel amounts, and end up with 0w35. would this work? Thanks

 

[smithph]

Use the Widman Viscosity Calculator to determine the resulting viscosity of the blend. You will need the cSt of each oil.

http://www.widman.biz/English/Calculators/Mixtures.html

 

[smithph]

SAE Viscosity ratings are ranges, thus you would never end up with a 2.5w35. Your end result would fall into one of the ranges defined in the chart below.

https://bobistheoilguy.com/viscosity-charts/

 

[CharBaby]

WELCOME!

Yes, you can mix just about any oils together including conventional w/synthetics without harm.

However, because the oil is measured in Centistokes(cST), the 1st#... 0 or 5 or 10 & 2nd#...20 or 30 or 40, would be a measurement of the cST(range). So you would end up with either a e.g.(5W30/0W40) with a higher 30 wgt or lower 40 wgt. Same with any mix of oils(0W30/0W40). Much to learn on this site and too much to discuss in just a few words.

Others can explain it better and in more detail. But, I encourage you to rear OIL 101(or whatever it's called), here at BITOG!

 

[ARCOgraphite]

No such thing as "35" grade or "2.5W".

The SAE grades have a RANGE, the winter rating spec has a range.

In your example, the 5w30 + 0w40 could become 0w30 or 5w40 - more likely it would be 5w30 but more toward the top of the viscosity range (high limit) for a 30 grade.

 

[Whipcitywrencher]

Thanks everyone, Widman calculator cool stuff

 

[Dallas69]

You better watch out for the never-mix crowd hanging out here.
They will put a curse on you.

 

[SilverFusion2010]

Originally Posted By: Dallas69
You better watch out for the never-mix crowd hanging out here.
They will put a curse on you.


I mix when I top off sometimes, if wally world doesn't have the exact Xw I filled with. If you stay in brand there's not really anything to worry about.

 

[Shannow]

Here's the new J300 (2013), showing the viscosity ranges that have applied since 2013...

As others have described, the oil will have to fit in one or the other of the grades.

The mixing calculators are pretty accurate on monogrades, but oils with viscosity index improvers are close to not so close in actual fact (member KCJeep had quite a bit lower than the calculator when he tested his).

As to two 0Ws remaining 0Ws when mixed, that's a guess that's not necessarily (or likely ???) going to happen...and you can't calculate the HTHS of the mix without converting Cp to Cst at 150, mixing in the calculator, and converting Cst back to Cp.

So a 0W30/0W40 mix is likely to be a heavy 30, or not quite a light 40, as the 0W40 has an HTHS viscosity requirement of 3.5, and most 0W40s aren't much higher than that in the bottle.

 

[Shannow]

Originally Posted By: Dallas69
You better watch out for the never-mix crowd hanging out here.
They will put a curse on you.


yeah, I know that some feel that mixing cures male pattern baldness and the heartbreak of psoriasis, while guaranteeing performance in the bedroom...but it just ain't so...

 

[smithph]

Originally Posted By: SilverFusion2010
Originally Posted By: Dallas69
You better watch out for the never-mix crowd hanging out here.
They will put a curse on you.


I mix when I top off sometimes, if wally world doesn't have the exact Xw I filled with. If you stay in brand there's not really anything to worry about.


Ditto. One of my vehicles has a 6.5qt sump. I will usually dump a 5qt jug of 5w30 down the fill hole followed by 1.5qts of whatever I have. Usually the same brand but sometimes a different viscosity.

I also experimented with the Caterham Blend

 

[blupupher]

Originally Posted By: Shannow
yeah, I know that some feel that mixing cures male pattern baldness and the heartbreak of psoriasis, while guaranteeing performance in the bedroom...but it just ain't so...

as well as others saying it will create male pattern baldness, give you psoriasis, and make your genitals shrink and keep you flacid, but it just ain't so...

 

[Dallas69]

Not bald yet but my eyes are bad

 

[Shannow]

Originally Posted By: Dallas69
Not bald yet but my eyes are bad


LOL, so the curse worked !!!