The Color of Oil Tells Nothing

[LeoStrop]

I would say that the color of the oil tells...something. If the oil is changing color, it means that something is happening with the oil. Although this is the normal transformation, if you are comparing apples to apples, then maybe you can take something out of it. If you take a neglected engine and do a flush only with new oil, the first time you drain the oil it will be darker than the subsequent flushes. But i believe that the intention of the OP is to say that you can't determine if the oil is good or bad just by looking at its color. The oil on my ethanol car always looks brand new on the dipstick, that doesn't mean it is still usable after the end of an OCI.

 

[T-Stick]

The categorical statement of this thread is categorically wrong and cannot be substantiated. There are certainly sometimes when an oil changes color that it does mean something and you only need one incident/scenario to disprove the proposition of this thread. One of those is that frothy oil means something wrong is going on--likely antifreeze or moisture. So there the statement has been disproved.

 

[zeng]

Originally Posted by OilUzer

Originally Posted by zeng

... Besides, all 3 oil samples demonstrate good and more than adequate detergency/dispersancy capabilities and are fit for continuing service, inc 38k and 6k samples. Fuel dilution problem (if any,) seems to be absent in all 3 samples. Just my Edit: Also absence of coolant issue.

zeng, I'm going to post picture of my used oil and have you analyze it. I like your confidence!

You're welcome to share blotter spot pictures with a view of guesstimating as to an used oil residual condition.. Blotters of 10k and below in typical Asian engines are generally boring , IMO.

 

[Ihatetochangeoil]

Originally Posted by T-Stick

The categorical statement of this thread is categorically wrong and cannot be substantiated. There are certainly sometimes when an oil changes color that it does mean something and you only need one incident/scenario to disprove the proposition of this thread. One of those is that frothy oil means something wrong is going on--likely antifreeze or moisture. So there the statement has been disproved.

Sir, you are absolutely right (I agree that antifreeze or moisture in your oil is visually apparent); and you are absolutely wrong. Page 1 of this thread I stated (ASSUMING a normal, healthy engine). Did you comprehend what you read prior to "disproving" it? ... Or can you determine the TBN, wear metals, contaminants, etc., visually?

 

[Ihatetochangeoil]

Originally Posted by LeoStrop

But i believe that the intention of the OP is to say that you can't determine if the oil is good or bad just by looking at its color.

AGREED. THANK YOU.

 

[Ihatetochangeoil]

Originally Posted by Garak

Card stock would be better for blotter tests. In any event, no, colour means nothing, unless something is totally out of the ordinary. If I'm using the same oil all the time over the same intervals and something goes totally weird, like milkshakey or black when it never gets black, then it's time to pay attention. Other than that, forget it.

Here are the mileages and the Top spots are on card stock. Sorry I've been gone so long on this thread; I've been working killer overtime the last couple weeks.

 

[zeng]

Thank you for the update.

 

[DGXR]

Give the blotters some backlight. That really helps me see the rings of particulates and fuel present in the oil.

 

[4WD]

Yep, you see coal black and very thixotropic oil in a motor that is typically brown + thin/shiny at the same miles - might be suspect. (oxidized oil)

 

[T-Stick]

Originally Posted by Ihatetochangeoil

Originally Posted by T-Stick

The categorical statement of this thread is categorically wrong and cannot be substantiated. There are certainly sometimes when an oil changes color that it does mean something and you only need one incident/scenario to disprove the proposition of this thread. One of those is that frothy oil means something wrong is going on--likely antifreeze or moisture. So there the statement has been disproved.

Sir, you are absolutely right (I agree that antifreeze or moisture in your oil is visually apparent); and you are absolutely wrong. Page 1 of this thread I stated (ASSUMING a normal, healthy engine). Did you comprehend what you read prior to "disproving" it? ... Or can you determine the TBN, wear metals, contaminants, etc., visually?

I am pointing in particular to your thread heading. But--even with your first post explanation it still is NOT categorically true. You would need to test every possible scenario before you could make such a statement. Some oil will turn darker as it depletes and I have seen that predictably as it nears the end of an OCI. If you had said the percentage of depletion cannot be calculated by oil color that would be true. The statement as it stands certainly has not been substantiated by pouring a couple samples on white material.

 

[T-Stick]

Another example where this assumption is wrong ... Cold weather with morning sun warm-ups on the block, accompanied by short tripping, will build up moisture in oil with a mechanically sound engine. You should be watching your oil for moisture and changing it or driving some longer trips to burn it off. This is really important on farm tractor hydraulic/transmission with shared sumps. They will condensate from just sitting through the winter and build up moisture content that will be detrimental and potentially freeze up hydraulics. You rely on the visual for a warning because a lot of fluids will repel the water and make it visible. You typically can't heat the transmission enough to burn it off. At a minimum you need to drain off the bottom and top off again. Both visuals and labs have their respective places. It's not an either or situation.