Can you mix 5w30 and 10w30?
 

So, i just put oil back in my car after drilling and tapping my oil pan. However, i got 3 quarts put in when i realized that one of them was 5w30 and the others were 10w30. They mustve gotten mixed up at autozone somehow. Anyway, should i drain $24 worth of oil or just run with it?

I don't see a problem with it.

ive done it lots of times with my old civic, i dont know what the effects are,
but i didnt see anything happen over the 2 years i drove it,
and i mixed alot, civic liked to leak oil from oil pan, so i added w/e i could find

It will make 7.5w30.

No you can't!

The Hydrocabons molecular structure is different, the 5W will seperate from the 10W. When this happens, out gassing occurs. This outgassing of Hydrogen will dry out your valve seals, and your Hydraulic lifters will collapse.

Same thing happens when you mix Synthetic with Dino oil...

Oh. I've never heard this. I guess the OP shouldn't do it then. Thanks for the info.

i just googled this for a few mintues,
everywhere i looked said its not a problem
i checked a few dif forums ,
as long as pressure is good,
there shouldnt be a problem.

jefe - please back up ur info, if u r indeed correct, ide like to have proof,
where did you find out about the hydrocarbons?

Done lots of reading on it and there is no problem with mixing.

I'd like to see whatever he's read to think they aren't mixable.

:friday:

well, i wont worry about it then. thanks for the help!

it's fine, makes the mixture whatever it mathematically comes out to be

:giggle:

Everyone is so serious around here lately...

IT WAS A JOKE PEOPLE

I can't believe people didn't get it. Read the whole post.

I hear your muffler bearings will seize and your airbag fluid will freeze up.

you know if this was posted on m.net, there would be a thread here making fun of it.

yeah, youre probably right... better to be safe than sorry?

Just curious....if mixing is ok then what what the hell is the point of selling all different types of oil like 5W30, 10W40, etc??? Also it was my car I think I would rather dump that oil put all the same type. Is $24 dollars worth of oil worth the cost of a motor if in case something did happen.

Zarish, you can't be serious. That's like asking "Why do they sell both Rum and Coke?" Just because the two are inter-mixable does not mean they are the same.

0w20 is a thin oil. 20w50 is a thick oil. Some engines require one, some engines require the other. That's why they sell both types. If you mix the two together, you will in fact get a homogeneous mixture rated somewhere in between the twp grades. The engine won't blow up, nothing will settle out of anything else, lifters will not collapse and seals will not fail.

@Joe Perez,

"Just because the two are inter-mixable does not mean they are the same."

This is exactly why I asked, your answer is within your own question. Anything can be mixed if you want to mix it, but that doesn't mean it will be ok to do so. You talk about rum and coke? Even rum and coke will effect your body and organs in a certain way, yes you will not die from it, but it will effect your organs in the long run. I know what you guys are saying, but I was just wondering how the oil mixture will effect the seals? There are two different viscosity oil in the engine flowing through. There is got to be more to this. Not to make an arguement out of it, but like I said I am curious to learn more cause I personally think its no simple as it has been made to look.

ok, simple english, all oil is the same basically, some thicker some thinner, you take two different viscocities and you mix them you will a third viscocity somewhere in between the two you mixed...does that make more sense?
not trying to be an ass, just trying to help you understand it