I usually run Amsoil in the crankcase, but last time Royal Purple was much more affordable. I have 2 quarts of each left over, has anyone mixed brands before?

 

Sounds like a bad idea to me.

 

Why? Just because?

 

I have 3 cars that take 5w30. I buy whatever is in sale in a 5 qt jug. Each car takes 4 qts, so I end up combining the 2 or 3 partial jugs into 1. I may have 2 or 3 different brands of 5w30 in the same bottle. Been doing it for yrs.

 

Bad idea. Different manufacturers use different supplements/additives to achieve their standards. What happens when those chemicals mix is unknown.
You want to be guinea pig? Go ahead and let us know.

Disclaimer: Do not blame me if your lubrication system gets clogged or some metal parts suffer from some weird chemical reaction.

 

Read the manual and it will say why. Seriously under maintenance,oil change,read it will say why!!!!!!!!!

 

It probably is rather harmless with regular oil, synthetic oil is different animal.

 

That never occurred to me, I'll check it out. Thanks.