The color of used oil tells us....

[kschachn]

About the only one I can think of would be soot, but you would have to specifically ask for that parameter. And one would think that you'd have to have a calibrated eye to correlate the visual to a specific loading.

But TBN? Wear metals? Viscosity? Presence of water or antifreeze? I doubt it.

 

[Whimsey]

The oil on our two Ford 4.6's comes out slightly darker than when new, even after ~8,000 miles. The same with my 2.0 Zetec. I did an UOA on that and after almost 8,800 miles the UOA was great and there was still plenty of life left in the oil according to the TBN. Now our new 2.3 EcoBoost in our 2017 Explorer goes in light honey and comes out REAL dark whether you run it 3,200 miles or 7,000 miles. I did an UOA for the 7,000 run and it had great wear numbers and there was still usable life left in the oil via the TBN number. This engine being DI and Turbo is obviously rougher on the oil appearance than the port injected engines but was still quite usable.

Whimsey

 

[Indydriver]

I’ve been changing oil for 45 years. It would be foolish to ignore your wonderful, God-given senses. You can tell a lot about the condition of the oil through sight, smell and feel.

If the oil is black and reeks of gasoline at 2500 miles are you going to ignore it just because you’re “supposed to get” a 5000 OCI?

 

[jongies3]

I don't know how that happens unless you change it within a thousand miles. My Toyota always comes out dark brown and my diesel oil is always black as hot tar when it comes out. The only one that comes out semi clean is my ATV's oil, since I change it almost monthly. Shared sumps are much harder on and shear oil fast, plus it's operating in constant dusty, wet and muddy conditions so I change it much more often than I probably should but it's for a peace of mind.

 

[Gebo]

All of my cars get really black in 5000 miles.

 

[StevieC]

Originally Posted By: Gebo
All of my cars get really black in 5000 miles.


Racist.

J/K

 

[69GTX]

I think used motor oil looks lighter than it truly is when seen on dipsticks and when pouring out (back lit) of your oil pan. If you want the true color of it, then look at it sitting in a container with a white bottom, and least 1/2" in depth. I do 1,000-1,200 mile M1 oil changes on one of my cars and it always looks dark by 1,000 miles when sitting in the oil waste pan....despite looking honey bronze on the dip stick.

I find the true color of used oil to be helpful (ie sitting in a pan). Why eliminate one of your senses? Don't hang your hat on the dip stick color. Use a black painted dip stick and see if that changes anything......

 

[turboseize]

The colour of the oil does no tell much, unless you know how it looked like when it went in.

This is Shell Helix Ultra 0w-30 AV-L after 9494 km / 5900 miles in a vintage Saab 900 turbo. (2.0 litre turbocharged petrol inline 4, turbocharger is a Garret T3 which is NOT water cooled and relies on oil for everything; car is supposed to have 160hp but dyno'd at slightly above 190hp with 100RON fuel.)

I've seen new oils darker than this.

And this is fresh AV-L directly after the oil change (has been running for less than a minute). With natural lightig, you could hardly see the oil on the dipstick...

 

[i_hate_autofraud]

Originally Posted By: Kuato
Originally Posted By: ZZman
The color of used oil tells us....


Next to nothing - at least not reliably, and between platforms. For one vehicle using the same oil, maybe.



After using a pair of FilterMags and magnets inside the spin-on oil filter on a late model
GM GAS engine for the last 4 yrs, my oil stays amber colored for 7-8 months, 8,000 - 9,000 miles!

This and the UOA tells me the oil is not 'dirty' but is loaded with all sorts of wear metals
when it finally turns black!

Auto makers and oil companies want us to believe the oil has "dirt" in it when it turns black,
they don't want us to know it's mostly wear metals! Filter makers wanna keep a lid on that too.
As a teen when I did my first oil changes on my own, I likely would have been freaked out had I
known about wear metals in the oil! Imagine how many owners would unsatisfied if they knew black oil is
loaded with metals!

Vintage engines with lots of blow-by can have 'dirt' as well as lots of metals too. Diesels are
noted for having soot in the oil that on it's own would turn the oil black.

 

[1JZ_E46]

If it's more red in color it means the oil is doing its job at cleaning up varnish and deposits.

 

[SilverFusion2010]

Blow by will darken oil. Cleaning up sludge will darken oil. Wear metals will darken oil.

For color to tell you anything definitive you need to know the history of the engine. GDI or TGDI engines will darken oil fast because they produce more soot similar to a diesel.

If you've got an old beater that runs good but turns oil coal black in 1000mi I'd start thinking about pulling valve covers to have a look. Or just change it at 1000 miles a few times with cheap HM oil to see if the darkening slows.

Oil color can be an indicator, but an indicator of what exactly is the problem.

If chunks come out when you drain the dump it's time for some short oci to get that mess out.

Hope this helps