# viscosity calculators?

Status
Not open for further replies.

#### jstutz

I have been calculating, using the ecko viscosity calculator, the viscosity of many differnet popular oils at temps from 0F to 230F. I come up with some interesting curves. If i knew how to attach an excel sheet to this forum i would share it. I dont however believe the results 100%. I believe it is becuause the vairables are going to be different based on the qualityh of basestock and the blended % of PAO. Does anyone know how to calculate Viscosity based on the different basestocks or the amount of PAO blended with x amount of group 3.

Last edited:
Very nice, unfortionally i have went thru the trouble of making basically the exact same thing. But i dont believe that taking V@100C and V@40C only can result in acurate calculations if you are asuming that all basestocks and blends react the same over temp. True?

It's a log function, regardless of base oil type.

Originally Posted By: jstutz
Very nice, unfortionally i have went thru the trouble of making basically the exact same thing. But i dont believe that taking V@100C and V@40C only can result in acurate calculations if you are asuming that all basestocks and blends react the same over temp. True?

When you use a chart like Rhomax or Widman, you are really working with close enough results from 40C to 100C. The problem is VII. What kind and how much does brand X use? VI is measured using 40c to 100C viscosity. It is within this 40C-100C that VII mostly take effect. The actual viscosity index of the fluid AFTER the VII's are done doing there work (after they've fully uncoiled) will likely become a lot lower. I don't know where this max temperature lies, and it would be different for each brand and maybe even grade, but it is just good to understand that any calculations at high or low temperatures using viscosity index on a fluid fortified with VII's may not be correct.

Did the rhomax tool http://www.rohmax.com/product/rohmax/en/about/calculation-tools/pages/default.aspx used to give the same results as the widman? Just wondering.
What FrankN4 writes above however, makes me wonder if there is any meaning creating lists such as the one uploaded at prcclub.gr ? Ignore the Greek, just notice the 4 viscosities (2 calculated and the other two in the middle from the manufacturer)
Note that the oils in the list are high quality (mainly GroupIV/V) for which composer was able to find specs.

Status
Not open for further replies.