Blending Viscosities Calculator

Status
Not open for further replies.
Joined
Oct 6, 2008
Messages
1,595
Location
NC
Guys, a few years ago i put this calculator together , in excel, to share with BITOG Members. Some of the information in it is outdated but the tool is still very handy. I have seen a lot of posts asking questions about viscosity, blending different oils, and cold weather performace of particular oils. Please keep in mind that the equations used have higher error ratios as you go further from the numbers that you input. Anyway take a look at it and if you have any questions or comments please PM me as i have been very busy and may loose site of the post. Ill try the best i can to answer any questions should there be any.

https://docs.google.com/file/d/0B6pXF6fW...dit?usp=sharing
 
One side note. Google has there own viewer and the equations do not work with it. You have to actually download the .xls file then modify it as you wish.

Also i should list what the tool does.

It will:
Graph up to three different oils
calculate VI from known viscosities
Allow you to blend two different oils and see the resulting viscosity from the misture.

You will need basic information such as 40 and 100C viscosity in cSt.
 
Last edited:
I have not got it to work in google sheets. The graphs dont come in when i use google sheets
 
But this just does it for virgin oil. What about oil with 100 hours or 1000 hours. There is plenty of good oil available at various weights, do not see the point in mixing.
 
For old engines like mine. A couple of quarts 5w30 for starts, some 10w40 for highway oil burning. It likes blends, I can tell by the idle and the vvt-i ticking or lack of. His sheet tells me which way to blend by qt for summer and winter.
 
Using the calculator to check 3 Mobil 1 grades: 0W20, 0W30 and 0W40.

As expected, M1 0W20 at 80C(13.4 cSt) is as thick as 0W30(13.6 cSt) at 90C and 0W40 at 100C(13.5 cSt).

With an oil temp gauge, if the OEM grade is at less than 100C after a long drive, then 1 or 2 thinner grades can be used without problem.
 
Originally Posted By: Donald
But this just does it for virgin oil. What about oil with 100 hours or 1000 hours. There is plenty of good oil available at various weights, do not see the point in mixing.


Sure there are plenty of weights available but maybe there are a few odd quarts laying around you want to use up and just would like to know about what your mixture is. As far as 1000 hrs on the oil, no calculator could predict that unless you did one for every specific oil. Different oils have too many properties to just lump into a single (simple) equation. I think i see your point though. I myself am not a big fan of mixing but every once in a while i have a few odd quarts lying around.
 
Originally Posted By: oldhp
http://www.widman.biz/English/Calculators/Mixtures.html

This is excellent chart to use.


This calculator should give you similar answers as the widman charts but it is local and you can manipulate as you wish. I just wanted something that i could control on my own and build my own data base that is important to me. Nothing is stopping you from saving one as 10w30 comparisons and others as something else or expanding on this calculator to do anything you would like to tailor it towards.

There is a lot that goes into blending a motor oil and it should most likely be left up to the blender as to what works best together. This tool just gives us something to play with.

Check out how thick some of the dino gear oils get when very cold.

If there was something else you all would like to see in the calculator i would be more than happy to add it to it.
 
Last edited:
Status
Not open for further replies.
Back
Top