blend your own M1 5W40?

bigpaulo · Dec 8, 2003

TooSlick, yes, yes, your point is valid, but what's wrong with my reasoning?

Besides, I'm hard pressed to find D1 anywhere handy where I live, whereas it's super easy to find M1 in the grades I listed.

And I doubt that mixing M1 will result in a sow's ear blend

I'm open to being convinced otherwise, though!

Eiron · Dec 8, 2003

I wouldn't even mess with the 5W-30. If you want extra additives, durability & hot vis, go with a 50/50 mix. If you want better cold flow with slightly "boosted" properties, use 75% 0W-40. (Or maybe 50/50 0W-30 & 15W-50?)

Dr. T · Dec 8, 2003

Hmmm, I come up with 8.375W-43.25.

That is, mixing 1 part 5w-30 with 2 parts 0W-40 yields a 1.75W-37.5. Thus mixing that with 1 part 15W-50 will yield the above number.

I think you're just adding fractions...an oil is not a fraction, but a viscosity which will dilute (thinner or thicker) the original volume depending on what viscosity is added to it...or is my thinking twisted???

satterfi · Dec 8, 2003

The Cameron Hydraulic Data handbook has a viscosity blending chart on page 4-35.

Two liquids of different viscosity will have a lower viscosity than the arithemtic mean of the two.

I have confirmed this experimentally.

Just buy D1 and be done with it.

bigpaulo · Dec 8, 2003

OK, I know my assumptions may be wrong...

But just for giggles, let's assume if you mix a N W M oil with a J W K oil in equal amounts, you'd end up with a blend that was like a [(N+J)/2] W [(M+K)/2] oil? That is, you can linearly combine them...

If we follow this, then we can make our very own Mobil 1 5W40 just by combining

1 part 5W30
2 part 0W40
1 part 15W50

Then you'd end up with (5+0+0+15)/4 W (30+40+40+50)/4 oil, which is exactly 5W40.

Sound logical to me, but I'm sure my assumption is somehow incomplete... discuss!

Last_Z · Dec 8, 2003

What would happen when the oil is heated by the engine? Will those numbers still hold?

TallPaul · Dec 8, 2003

quote:

Originally posted by satterfi:
The Cameron Hydraulic Data handbook has a viscosity blending chart on page 4-35.

Two liquids of different viscosity will have a lower viscosity than the arithemtic mean of the two.

I have confirmed this experimentally.

Just buy D1 and be done with it.

Excellent piece of information there satterfi!

Bob Woods · Dec 8, 2003

My understanding of PAO base stocks is that they are produced in different viscosities, 5w has smaller molecules than 10w, they add stabilizers to keep it from thinning out at higher temps. If you mix different weights together wouldn't you end up with oil molecules that look like this? OoOoOoOoOoOoOoOoOoOoO

TooSlick · Dec 8, 2003

Buy the significantly more expensive, higher quality, Mobil Delvac 1, 5w-40 as I have recommended on a # of occasions. "You can't make a silk purse out of a sows ear ..."

TS

TallPaul · Dec 8, 2003

quote:

Originally posted by Dr. T:
Hmmm, I come up with 8.375W-43.25.

That is, mixing 1 part 5w-30 with 2 parts 0W-40 yields a 1.75W-37.5. Thus mixing that with 1 part 15W-50 will yield the above number.

I think you're just adding fractions...an oil is not a fraction, but a viscosity which will dilute (thinner or thicker) the original volume depending on what viscosity is added to it...or is my thinking twisted???

You can't do it. There is not 8.375 grade. It is either a 5w or a 10w and you have to know the base oil viscosity for each one and then use the chart referenced above. Then for the upper number it is either a 30 or 40 weight (all these grade numbers represent ranges of viscosities). You would have to figure the amounts of viscosity improver (VI) additives in each different grade you are mixing, average the VIs, and then figuure out how they will act on the several modal base oil molecule size (0oOoo00OOoo0Oo). Mission Impossible! Mix it if you must, but if you want to know what you have, send it out for a viscosity analysis.

[ December 09, 2003, 12:39 AM: Message edited by: TallPaul ]

Lubricious · Dec 8, 2003

So what some of you are saying is, if you mix 2qts 10w30 with 2qts 20w50 you won't get a 15w40?

Al · Dec 8, 2003

quote:

Originally posted by Lubricious:
So what some of you are saying is, if you mix 2qts 10w30 with 2qts 20w50 you won't get a 15w40?

Bingo

TallPaul · Dec 8, 2003

quote:

Originally posted by Lubricious:
So what some of you are saying is, if you mix 2qts 10w30 with 2qts 20w50 you won't get a 15w40?

This is possible (since 15w and 40 are both SAE grades), but how can you be sure you are falling into this range? And then all your parameters (pumping viscosity, cold cranking, etc.) are likely affected by the bi-modal molecule distribution of the base oil. May not cold crank as well as a production 15w40 and may not stand up to heat as well either. I thought about doing this with Valvoline Maxlife since they don't have a 15w40. In fact I now have a mix of (don't laugh) 4 qts 5w30, 2 qts 20w50, and 1 qt 10w40 (and some other weird stuff not to be mentioned). Long story, but was test to boost oil pressure and as a result I am moving to straight 10w40. No more witches' brews for me.

bigpaulo · Dec 8, 2003

saterfi wrote
> The Cameron Hydraulic Data handbook has a
> viscosity blending chart on page 4-35.

Wish I had that handbook

I'll google it!

TallPaul,
"I think it's some kind of witches' brew!" - Homestar Runner

All,
Relax folks! I'm not about to try this witches' brew my car

So far, it's been M1 5W30 for me

Eiron · Dec 10, 2003

quote:

Originally posted by satterfi:
The Cameron Hydraulic Data handbook has a viscosity blending chart on page 4-35.

Two liquids of different viscosity will have a lower viscosity than the arithemtic mean of the two.

I have confirmed this experimentally. ...

Just out of curiosity, how did you confirm it?

Based on this, it sounds like a 50/50 mix of 0W-40 & 15W-50 would put you square in 5W-40 territory ...

quote:

Originally posted by TallPaul:
... There is not 8.375 grade. It is either a 5w or a 10w and you have to know the base oil viscosity for each one and then use the chart referenced above. Then for the upper number it is either a 30 or 40 weight (all these grade numbers represent ranges of viscosities). ...

Don't get blinded by these categories. As you pointed out, they're nothing more than ranges represented by an average "group" number. There indeed is an 8.375 viscosity & a 43.25 viscosity, even if there are no "labeled" grades identifying them.

[ December 10, 2003, 03:25 PM: Message edited by: Eiron ]

Dr. T · Dec 10, 2003

Ok..I hear ya...so rounding down slightly you would get a 5W-40...

What about talking the relativce cSt's of each and then combining them arithmetically? This would accont for a "thin 30" or "thick 40" and allow for some greater accuracy in determining the final number(s).

What does the "handbook" say the final viscosity would be with the above mix? Do they have a formula?

satterfi · Dec 10, 2003

quote:

Originally posted by Eiron:
Just out of curiosity, how did you confirm it?

I built a Saybolt viscometer so I can blend lubricating oils for my automatic chain oiler.

At first I was surprised at the results of blending two liquids of different viscosity. They always came out thinner than I expected.

I checked the fluid reference books I have and Cameron's confirmed my observations.

Just for giggles here's and example from the chart I refered to:

Mix equal parts of a 40 SUS oil and an 80 SUS oil.

The mixture will be a 50 SUS oil.

TooSlick · Dec 10, 2003

Given the Boston climate, I'd just run the 5w-30 for eight months out of the year and the 15w-50 for June-Sept.

The 5w-30 will flow better than a 5w-40 in cold weather and give you better fuel efficiency. The 15w-50 (which has a more robust add pack than the 5w-30), will give you better wear protection and less oil consumption than the 5w-40 during the summer....

You can basically do this with almost any modern engine, regardless of what SAE grade is recommended ....German vehicle manufacturers have been recommending different grades, depending on ambient temps, since the Stone Age ....

Any questions?

Eiron · Dec 10, 2003

Yeah!:

Waddaya do if your OCI lasts for 12 to 14 mos, thru winter startup temps of 5°F-10°F, & summer sitting-in-traffic temps of +100°F?

Oh, & your engine's turbocharged ...

JohnBrowning · Dec 10, 2003

I see no problem with blending so long as you are aware that your home brew is not going to perform like a product specificly engineered to meet the API grade you are trying to replicate. We have seen more then a few M1 and Delvac1 mixtures that have proved to be excellent. I think your goals dictate your course of action. I also agree that if you are going to do a blend you should send a sample of for VOA so you have some idea where you are starting at. In this case the base stocks and additive packages are simalr and you should have no problem with additive clash.

P.S. I think you would be better off with Delvac1 you can order it right here at Bob is the oil guy. The main page has a link to site sponors. CLick on the Mobil site sponsor.

blend your own M1 5W40?

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