Mixing/combining engine oil of different weights
08-10-2007, 09:11 AM
#1
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Mixing/combining engine oil of different weights
I just got a '92 LT1. About to do an oil change, and have a few bottles of Mobil 1 5W30 & 10W30 lying around. Is it OK to mix oil of different viscosities?
08-10-2007, 11:53 AM
#2
Team Owner
It is a common practice. You end up with slightly thinner or thicker oil depending on how you look at it.
08-14-2007, 07:08 AM
#5
Race Director
Be fine.........you can even mix dino/syth when you have to w/o issue 
I have done 15W-50 syth & 20w-50 dino 
I have done 15W-50 syth & 20w-50 dino
09-12-2007, 03:04 AM
#7
Race Director
Engine oil visc is increased by adding dissolved Kraton SBR rubber to oil.
The basic oil is all the same, add more Kraton rubber, the visc goes up, mix two different visc oil and you get something in between high and low.
Doug
The basic oil is all the same, add more Kraton rubber, the visc goes up, mix two different visc oil and you get something in between high and low.
Doug
09-13-2007, 05:45 PM
#8
A parts house guy told me that after running synthetic oil in an engine that you CANT go back to regular dino oil. I looked at him like he was insane, was he?
I ran synthetic in my C2 BB, it didnt like it so I went back to dino oil, I have not had any problems.
Is what he told me accurate? I think Not....
I ran synthetic in my C2 BB, it didnt like it so I went back to dino oil, I have not had any problems.
Is what he told me accurate? I think Not....
12-02-2007, 06:27 PM
#9
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I was told that if you add one or two quarts synthetic with 3 quarts standard during an oil change that the combination is almost as good as pure synthetic?? I only use synthetic in my vette, but it sounded logical??
