Blending advice needed

[jdeare]

Over the weekend my dad gave me a case of YB: 9 5W-20 and 3 5w30. My car uses 10w30 in the summer and can use 5w30 in the winter (01 Buick Regal 3800), although I used 10w30 last winter.

What can I blend with the 5W-20 to safely use it up? I found a thread with some kind of mathematical equation, but I'm terrible at math. I would use Pennzoil conventional for the blending as well.

This is mainly because I'm cheap (free oil... yahoo!)

 

[addyguy]

Well, the sort-of obvious answer would be blend YB 10W-40 with the 5W-20 to create something 'around' a 30-weight.

Its very crude, but I use 'straightforward math' when calculating blends, using the 100C visc:

So, you need 5 quarts, and the 5W-20 is 8.5 cst, and the 10W-40 is 14.0 cst;

8.5 times 3 is 25.5; and 14.0 times 2 is 28. 25.5 + 28 = 53.5. Divide by 5 = 10.7. So, 3 quarts 5W-20 and 2 quarts 10W-40 is a blend with a 100C visc. of about 10.7 cst.

That's how I do it....

 

[flwxman]

If it is that big of a deal and if they are still sealed, you could probably take the quarts of 5W20 to a walmart or other auto store and ask to exchange them with YB 10W30.

 

[jdeare]

addy, this makes more sense than the other thing I found. Thanks!

It's not a big deal at all. In fact my first thought was to dump the 5W-20 into a jug and recycle it, since I don't know anyone that uses 5W-20 and also changes their own oil.

 

[addyguy]

Hate to say it, but you could just dump the 5W-20 into your Buick. Most 10w30/5w30's shear down to a 20-weight anyway, so what harm would it do? YB 5W-20 is a VERY good oil!

 

[FrankN4]

You could mix 40% 10W-40 with 60% 5W-20 and get a product 100C cSt of 10.24. You could mix 50/50 and get a 100C cSt of 10.78.

There was thread several months ago complaining of Mobil 1 5W-20 shearing down so quickly, why use it. I pulled up every UOA on Mobil 1 5w30, Amsoil 5w30, and Mobil 10w30 going back to SL. It took an average of 5000 miles for Mobil 1 5w30 to shear down to the same viscosity as Mobil 1 10w30. Amsoil 5w30 did even better.

 

[bepperb]

I wouldn't dump it. Chances are good your next car will use it.

I'm not big on blending oil, but I'm sure you could come up with a suitable mix with some YBP 10w40.

 

[FrankN4]

Originally Posted By: FrankN4
You could mix 40% 10W-40 with 60% 5W-20 and get a product 100C cSt of 10.24. You could mix 50/50 and get a 100C cSt of 10.78.

There was thread several months ago complaining of Mobil 1 5w30 shearing down so quickly, why use it. I pulled up every UOA on Mobil 1 5w30, Amsoil 5w30, and Mobil 10w30 going back to SL. It took an average of 5000 miles for Mobil 1 5w30 to shear down to the same viscosity as Mobil 1 10w30. Amsoil 5w30 did even better.



That is 5w30 not shearing down, not 5W-20.

 

[Max_Wander]

Hey how did you calculate the viscosities? Is the Shell calculator back up!?

 

[FrankN4]

Originally Posted By: Max_Wander
Hey how did you calculate the viscosities? Is the Shell calculator back up!?

http://www.rohmax.com/rohmax/en/customerservices/calculationtools/baseoilmixtures/