Synthetic/conventional mix

5VZ-FE

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I just did an oil change and realized I accidentally put a 2 qts. of conventional oil in with my synthetic oil. I’m well aware of how stupid that was but I was rushing and had an extra 2 qts. laying around and I didn’t realize until I was done. Anyone know if it’s gonna be an issue? I’ve asked a couple sources:

My dad said that it used to be an issue but he doesn’t think it is anymore.

My uncle said the same thing, and my cousin called me an idiot.

I spent some time on Google, which said that it used to be an issue but isn’t anymore. I’m not sure if this means that oils have changed, or if this only applies to new cars…

Obviously I’d really like to not do another oil change, but I will if its an issue. I’m going down to Mojave this weekend so I want to make sure I’m in good condition.

I have 18 miles on the oil change.

Thanks
 
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I just did an oil change and realized I accidentally put a 2 qts. of conventional oil in with my synthetic oil. I’m well aware of how stupid that was but I was rushing and had an extra 2 qts. laying around and I didn’t realize until I was done. Anyone know if it’s gonna be an issue? I’ve asked a couple sources:

My dad said that it used to be an issue but he doesn’t think it is anymore.

My uncle said the same thing, and my cousin called me an idiot.

I spent some time on Google, which said that it used to be an issue but isn’t anymore. I’m not sure if this means that oils have changed, or if this only applies to new cars…

Obviously I’d really like to not do another oil change, but I will if its an issue. I’m going down to Mojave this weekend so I want to make sure I’m in good condition.

I have 18 miles on the oil change.

Thanks

If both oils were the same weight, I dought it will effect performance.
 
No problem, now you have a synthetic blend instead of full synthetic. Run it till next change and then pay more attention.
 
No issue. Honestly I'm not convinced there is any 100% synthetic. They all use conventional to some extent and synthesize the rest. So you got a blend and even full synthetic are technically blends to a degree. With that said I'm a fan of conventional for our motors given the era they were made unless you've modified for forced induction synthetic not necessarily needed and due to its thinner finer particles you may see leaks using synthetic sooner then if thicker conventional oil were uses. Sure you can get by using synthetic longer for more miles. But most of us here are current and keep current on routine fluid changes and check so conventional is my preferred
 
Seeing how forgiving these engines are, one could run ATF in the engine and it'll still truck on.

Please don't try it though.
 
Seeing how forgiving these engines are, one could run ATF in the engine and it'll still truck on.

Please don't try it though.


I actually ran a qt in my old 96 Saturn to try and help uncoke the oil rings. It would use a qt every 1000 miles.


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I actually ran a qt in my old 96 Saturn to try and help uncoke the oil rings. It would use a qt every 1000 miles.


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Works pretty good at gently cleaning sludge deposits too. A little more aggressive than regular oil, but way more gentle than an engine flush additive etc.
 
I actually ran a qt in my old 96 Saturn to try and help uncoke the oil rings. It would use a qt every 1000 miles.


Sent from my iPhone using Tapatalk

Did it help? The 7afe in my corolla has a bit of an oil drinking problem too. Known to foul the rings.
 
Did it help? The 7afe in my corolla has a bit of an oil drinking problem too. Known to foul the rings.


I used the ATF as a make up oil sometimes also. It helped. I eventually halved my oil consumption it 1/2qt per 1000 miles.

Diesel oil works good also. 5w30 Rotella T5.

BJ109 engine flush is another great product.

I did the ATF, Diesel oil, and the BG109. Over time I got it to 1/2qt per 1000.
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as far as the OP.....you will be fine.

off main topic but fits with above posts....
on the ATF in oil talk....at a shop I used to work at, we would occasionally flush an engine with ATF to unstick rings etc. On really bad ones, we would put atf directly into the cylinders and let it soak a day or two, spin it with plugs out to get rid of it. If doing a head gasket job, we would pull the heads, scrape off piston tops and then put atf in the cylinders and let soak while heads were off.
this is just what the old man and owner of shop had us do. so we did ( yes boss). I did see it unfreeze a tractor motor that had filled with water in the cyliders and sat for a year. ( that was a 50/50 mix of atf and acetone...sat for a few days and then it would spin,...pumped stuff out and started) The old guy swore by that mix.

If this new to me rig had not passed a compression check, i would have tried atf in the cylinders and let soak.


try at your own risk
 
Last edited:
as far as the OP.....you will be fine.

off main topic but fits with above posts....
on the ATF in oil talk....at a shop I used to work at, we would occasionally flush an engine with ATF to unstick rings etc. On really bad ones, we would put atf directly into the cylinders and let it soak a day or two, spin it with plugs out to get rid of it. If doing a head gasket job, we would pull the heads, scrape off piston tops and then put atf in the cylinders and let soak while heads were off.
this is just what the old man and owner of shop had us do. so we did ( yes boss). I did see it unfreeze a tractor motor that had filled with water in the cyliders and sat for a year. ( that was a 50/50 mix of atf and acetone...sat for a few days and then it would spin,...pumped stuff out and started) The old guy swore by that mix.

If this new to me rig had not passed a compression check, i would have tried atf in the cylinders and let soak.


try at your own risk
I've used the 50/50 trans fluid/acetone as a penetrating oil. It works pretty good too.
 
posible foaming

mixing different type of oils in general may cause foaming.
drive harsh for a while, check disptic.. it should have no bubbles,, if having some then its "maybe" foaming due unable to completely mix with each other.
 

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