mixing oil

letsgo19

Seaman
Joined
Dec 24, 2009
Messages
68
Is it ok if i mix 1qt of synthetic oil with 4qts of regular oil for my Mercruiser winterizing.
 

JoLin

Vice Admiral
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Aug 18, 2007
Messages
5,146
Re: mixing oil

Is it ok if i mix 1qt of synthetic oil with 4qts of regular oil for my Mercruiser winterizing.

It's called 'semi-synthetic', You can buy it over the counter, too. In this case it'd be an 80/20 blend instead of 50/50. No harm.

My .02
 

Brewman61

Ensign
Joined
Jun 10, 2010
Messages
996
Re: mixing oil

Motor oil, usually ok.

Outdrive oil? Nope. Don't mix Merc. High Performance Gear Lube with their Premium Gear lube.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: mixing oil

No you shouldn't mix the two, they are two completely different types of oil.
Just because you mix two type doesn't make it semi synthetic. Additives are used to blend the two together, not just pouring the two together.
 

scooper77515

Senior Chief Petty Officer
Joined
Sep 3, 2010
Messages
747
Re: mixing oil

No, Don't mix synthetics with minerals.

Did this once in my seadoo jetski, on accident (dealer sold me the wrong bottle). It turned into jello, and clogged my injectors, hoses, and filters.

Had to suck it all out with a wet-or-dry vac from tank and crankcase. New filters, new $75 dollar bottle of one gallon of the correct synthetic oil, and been fine ever since.

So, NO, do NOT mix synths with mineral oils.
 

letsgo19

Seaman
Joined
Dec 24, 2009
Messages
68
Re: mixing oil

For some reason i had a quart sitting around.At least i think its synthetic it says Quicksilver 25/40 but doesn't say" Synthetic" on quart bottle anywhere.
 

scooper77515

Senior Chief Petty Officer
Joined
Sep 3, 2010
Messages
747
Re: mixing oil

Again, DO NOT mix synths with mineral oil. Some may mix, but if they do not, you will have a major mess on your hands.

Go to the pwc forums, seadooforum.com, etc. There are hundreds of threads of horror stories of us guys accidentally mixing the oils and having to do craploads of work to clean our lines and systems out, and some just cratered their engines.

Here are a couple pics of what the oill looked like after mixing it and driving for a couple weeks. These pics are just the oil lines pulled loose, not drained yet. It came out THAT thick. The "leaves" on the oil sending unit are actually coagulated chunks of mixed oil.

Now if you still feel like you want to mix, go ahead...:rolleyes:
 

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HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: mixing oil

Go to the pwc forums, seadooforum.com, etc. There are hundreds of threads of horror stories of us guys accidentally mixing the oils and having to do craploads of work to clean our lines and systems out, and some just cratered their engines.

Here are a couple pics of what the oill looked like after mixing it and driving for a couple weeks. These pics are just the oil lines pulled loose, not drained yet. It came out THAT thick. The "leaves" on the oil sending unit are actually coagulated chunks of mixed oil.


Um......those are 2 stroke engines right?
 

scooper77515

Senior Chief Petty Officer
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Sep 3, 2010
Messages
747
Re: mixing oil

Yes. 2-stroke.

Are you saying that with 100% certainty you can mix 4-stroke synths and minerals?

We need to make this clear before anyone takes our suggestions and end up with a mess.

Personally, I will never suggest to mix any synths and minerals, just so they don't call me up later and tell me I screwed up their engine.

Just decide what you want to run, and run it. If you change your mind, do an oil change, but don't start adding one to the other. Just in case.
 

KJSmitty

Petty Officer 2nd Class
Joined
Aug 9, 2008
Messages
179
Re: mixing oil

Had several Seadoo XP's and no, you did not want to mix "that" synthetic/injected oil...

4 Stroke / oil is definitely different and I have never seen a case where someone mixing it caused any issues. Would I do it just to use up a qt - not me personally. Would I if I needed to get home and was low on oil, sure.

Also, I don't remember where yet a while back I remember reading where today's oil, synthetic or not, different brands etc, had to be compatible with each other.

Cheers
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,524
Re: mixing oil

4 Stroke / oil is definitely different and I have never seen a case where someone mixing it caused any issues. Would I do it just to use up a qt - not me personally. Would I if I needed to get home and was low on oil, sure.

Ayuh,.... Any Oil is Better than No Oil at All.....
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: mixing oil

Yes. 2-stroke.

Are you saying that with 100% certainty you can mix 4-stroke synths and minerals?

You just cannot make blanket statements regarding engine lubricating oil based on anecdotal "evidence" using 2 stroke oil. 2 Stroke oil is NOTHING like 4 stroke crankcase oil.

It's like comparing motor oil to canola oil.....

Just about every motor oil manufacturer indicates it is "ok" to mix them. They also indicate that you will not get the "synthetic" benefits, but it will not 'hurt" anything.

From Mobil:

Can different synthetic motor oils be mixed together?
spacer.gif


Mobil 1 is fully compatible with conventional motor oils, semi-synthetic motor oils and other synthetic motor oils, should it be necessary to mix them. However, it is important to note that the superior performance of Mobil 1 will be reduced by diluting it in any way.



From Valvoline:


  1. Can you mix different types of motor oil? For example, synthetic and synthetic blend or regular and synthetic? Is this going to cause problems?
    Mixing synthetic and conventional oils will not cause any problems. The oils are compatible with each other.



From Amsoil;

MIXING AMSOIL
AMSOIL Synthetic 5W-30 Motor Oil is compatible with conventional and synthetic motor oils. Mixing AMSOIL motor oils with other oils, however, will shorten the oil life expectancy and reduce the performance benefits. AMSOIL does not support extended drain intervals where oils have been mixed.



(Amsoil says this in general about all their oils.....I didn't look at 2 stroke oil........THIS ISN'T A 2 STROKE FORUM)




I am also not advocating any of the above oils for use in any engine....Marine or otherwise.......


But it's clear that manufacturers that must stand behind their products wouldn't make statements that they'd have to defend in court if they were completely false (and caused damage)



Notice that I didn't use examples from discussion forums.:rolleyes: A lot of people there make claims that they cannot or don't back up.


The manufacturers that DO recommend AGAINST mixing certain kind of oils with "others" indicate it......IN BOLD PRINT..... Like Mercury High Performance Gear lube.


From Mercury Marine about Mecury HP Gear Lube.......


  • Since no industry-wide standards exist concerning marine gear oils, it is essential to use products such as Mercury High-Performance Gear Lube which has been specifically designed and tested for marine applications.
  • DO NOT mix with Mercury Premium Gear Lube.
  • Provides warranty protection for all Mercury MerCruiser sterndrive and Mercury, Mariner and Force outboard lower units.
  • yada yada yada.....


(emphasis & yada mine);)



So, for the original poster.....

Is it ok if i mix 1qt of synthetic oil with 4qts of regular oil for my Mercruiser winterizing.
Yes, it won't hurt a thing.... It won't help anything either....

like a famous person once said.....
Any Oil is Better than No Oil at All.....
....

I would save the 1qt of synthetic for when I get the other 4 qts....



Cheers,


Rick
 

bigskiohio

Master Chief Petty Officer
Joined
May 3, 2008
Messages
882
Re: mixing oil

i mix all the time in my car if i do a oilchange with syn then need to top off in between i will use regular oil , car has 200,00 plus miles on it . how did we jump to 2cyl. seedoos on this forum?
 

scooper77515

Senior Chief Petty Officer
Joined
Sep 3, 2010
Messages
747
Re: mixing oil

Sorry to get semi-off-topic. Original poster asked...
Is it ok if i mix 1qt of synthetic oil with 4qts of regular oil for my Mercruiser winterizing.

And before someone did a search and got all kinds of "oh, yeah, it is OK" answers from this post, I wanted to make sure that some 2-stroker didn't read it and get the idea he could mix his oils (which he most definitely should NOT!).

so it may be OK for 4-stroke oils, we need to make it clear, since some guys, maybe MANY on this forum, are using 2-stroke engines.

The consequences of mixing synth and mineral oils CAN BE very bad, if the two oils do not blend well.

That being said, I would never mix them. AGAIN. Been there, done that, nearly lost the motor!
 
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