Is it acceptable to mix oils.

For example if you have 4 quarts of Quaker State 5w-30, can you mix with one quart of 5w-30 Castrol.


If you have one quart of 5w-30 quaker synthetic blend, can you mix with 4 quarts of 5w-30 quaker state oil


Thanks.

 

Yes, no issues.

 

Been doing it for decades. My poor Corvair has had 5w-30, 10w-30 and 10w-40 at the same time. It seems like every time we get a new car, it uses a different weight and end up with a case or two of something I don't need anymore. I have a couple cases of 5w-20 from my Fiesta. Too light for the Corvair as it runs over 200 degrees. Our Hondas both take 0w-20, and I not going to risk putting it in them.

 

I would advise caution when mixing oils from different manufacturers as some additives may be incompatible

 

Meh, every manufacture has a FAQ on their web site, and last time I checked, they all stated they were compatible with pretty much every other contemporary oil except Group V (ester based) Synthetic oil.

 

Any oil is better than no oil, I ran 10-30 and 15-40 in my elcamino and it didnt know the difference. Hell it was just happy to have oil in it. No issues.

 

What you say is very highly likely for any generation of El Camino engine what with the exceedingly loose tolerances and such; put 15W-40 in a modern Honda engine and all will not go quite so well for the motor.

 

Read my post,,any oil is better than no oil...it was a hi performance built 362 cubic inch small block and i assure you it was not loose... 96 vortec block bored .060 vortec heads. ect,,ect,,/ ANY OIL MIXED OR NOT IS BETTER THAN NO OIL,,in a pinch i have run the same 15-40 delo in my accord with zero issues, you have a right to your opinion but what you say is not sacred by any means..carry on.

 

You missed my point, at its very best, your small block Chevy motor has no were near the close tolerances of a modern motor.