Oil....

This should be a short topic.
I have about 3 half filled containers of different brands of oil.
All are for the diesel main engine.
They all have the same viscosity.
Is it safe to mix them all together and use in my next oil change?

Let imagine you are your engine, and you have 3 bottle of wine half full in front of you. Would you mix them all to make a maybe good bottle of wine?

Depending of what kind of wine drinker you are, you may or may not. If you don't care about taste and have an old iron palate you may not see the difference. If you are a highly trained taster, an athlete of wine you will not like it.

Your engine is the same


L

It may be fine but I don’t know for sure or not. I only use 1 brand and then stick to it so I don’t have odds and ends of oil around. I use Rotella in the diesels and transmissions.

Consume them all.

markpierce said:

Consume them all.

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I don’t think that would taste very good...

OldDan1943 said:

This should be a short topic.
I have about 3 half filled containers of different brands of oil.
All are for the diesel main engine.
They all have the same viscosity.
Is it safe to mix them all together and use in my next oil change?

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Assuming these are gallon containers, is money so tight that you can't buy another gallon and a half of your favorite oil?

Ted

Comodave said:

I don’t think that would taste very good...

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Well no, but I think he meant the wine Lou mentioned, rather than the oil.
Dan,this problem seems the result of changing oil brands too often. Would you top up with a different brand if needed? Probably, if the specs were the same. Is this so different?
I doubt it`s a question of saving a few $, more using/not wasting some perfectly good oil. Could even be the same oil with different brands.

BruceK said:

Well no, but I think he meant the wine Lou mentioned, rather than the oil.
Dan,this problem seems the result of changing oil brands too often. Would you top up with a different brand if needed? Probably, if the specs were the same. Is this so different?
I doubt it`s a question of saving a few $, more using/not wasting some perfectly good oil. Could even be the same oil with different brands.

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You have to spell it out for me...

I've mixed oil with the same rating all my life. Also I got longer intervals between overhaul with my engines.
Often running commercial boats, when moving between ports, the same brand of oil wasn't always available. So you either store a couple brands of oil until it's available again, give it away, or use it. Tugs usually have a new oil storage tank filled from the deck. If you couldn't use the oil you'd have to pump it to a waste oil tank or somehow pump it ashore.

All lube oils have a different additive package.
You may have oil w almost none of one kind of additive and too much of another.
So mixing is not ideal.
Dan, are these “containers” Quarts or gallons?

Oils have gotten really sophisticated over the last 20 years.Back in the day we would put anything in but not now.In the 70s i worked at a gas station and we dumped anything left in a can and sold it as bulk .Now i save the remainders for lawn mowers and lube for drilling steel and stuff like that .

Is it safe? Yes. Desirable? If you take routine oil samples, no. What brand would you list as the base oil? If it were unsafe the manufacturers would have warnings not to mix brands.
Why not save the jugs for a complete change out of the generator 2 times and the last for the next change of the main? Buy an extra quart or two of like kind to complete the change as needed.

Lou_tribal said:

Let imagine you are your engine, and you have 3 bottle of wine half full in front of you. Would you mix them all to make a maybe good bottle of wine?

L

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I have been known to do that on more than one occasion after a pissy lunch leading into pre dinner drinks, a great curry and a selection of cider and reds.(late 80's early 90's, put down the tools for a while and wore a suit and tie and fun a plenty was had)

I'm still here, didn't die once.

Read the labels. I think you will find that, assuming the same viscosity, 15W-40 for example, and the same SAE designation, those oils can safely be mixed. Yes, additive packages may be slightly different but that is of no measurable consequence.

OldDan1943 said:

This should be a short topic.
I have about 3 half filled containers of different brands of oil.
All are for the diesel main engine.
They all have the same viscosity.
Is it safe to mix them all together and use in my next oil change?

Click to expand...

Nomad Willy said:

All lube oils have a different additive package.
You may have oil w almost none of one kind of additive and too much of another.
So mixing is not ideal.
Dan, are these “containers” Quarts or gallons?

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Gallon containers.

I have wondered about mixing additives also but, reading the containers.... they all claim to "meet or exceed" the same standards.

And that is my point. If they meet or exceed the standard, then mixing is just fine. Additives then are immaterial.

OldDan1943 said:

Gallon containers.

I have wondered about mixing additives also but, reading the containers.... they all claim to "meet or exceed" the same standards.

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"I have wondered about mixing additives also but, reading the containers.... they all claim to "meet or exceed" the same standards."

The "standards" are that the oil will function in an engine and give the same lubrication with out harming the engine

The additives can be 15 to 20% of the oil content and there is NO standard that sez you can mix and match from different refiners..

A really early design like a 2 cycle DD from 1930s wont care as long as the oil is CF II, .

The old CD requirement for light truck or farm implement seems happy with whatever is dumped in.

Personally I would never mix brands on a newer engine , the turbos and exhaust system might be at risk.

https://www.bobistheoilguy.com/motor-oil-101/
This is probably TMI, but a good rainy day read. Personally, I would mix them. Use them to top up, especially if you have an old motor.

The wine comment is so funny. I did just that with 4 part bottles of wine and I still haven't heard the end of it form the buddy wine connoisseur!! In my defense they were all red!

I would imagine that the oil lab analysis would be more useful to you if you used the same brand and spec all the time. If you do not do regular oil analysis of your sump oil, then you are the oil-equivalent to that wine heathen Floater where mixing oil would not make any difference.

As long as the SAE ratings are compatible with the engine requirements( the ratings dont have to be the same just meet or exceed the specs) I would do it.

When makers do it with synthetic and dino oil they call it a blend.

I try not to mix oils, but I think there is about 0% chance of it causing any harm.

I do keep random left over oil in jugs for chainsaw bar oil, oil squirters in the shop, lawnmower and tiller engines, etc.

The very expensive boat diesel gets the consistent stuff.

Guys, I was an engineer, bad idea mixing wine in your oil. Tastes terrible.

Motor oil: I would use over a period of time to top up.

Gear oil: Don't mix brands. Have personally seen zinc precipitate out of EP gear oil and form massive sludge deposits due to incompatible additive packages.

Who has leftover wine?

bayview said:

When makers do it with synthetic and dino oil they call it a blend.

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When wine makers do it they call it Bordeaux or Burgundy, sometimes Chianti or even Meritage. There are very few true single varietal wines, especially reds which are nearly always a blend of two or more varieties. They are not always labeled as such on the bottle......

Use them in your old truck or car. A lot cheaper to replace a gasser than a diesel. (If it ever comes to that)

pete

Lot's of urban myth...

Absolutely fine to mix three brands of modern diesel spec oil.

GT6 said:

Lot's of urban myth...

Absolutely fine to mix three brands of modern diesel spec oil.

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Have any sources/links?