Should Oil be dark before you change it

[Realtech214]

It seems that if you were to follow to GM OLM the oil would be dark and pretty black when it indicates to CHANGE ENGINE OIL. I know black oil is not necessarily bad oil but i guess its pretty normal too? I have always changed mine before it gets that dark.

 

[Danno]

Color varies depending on the engine - miles, time and/or UOA would be the typical measures for changing oil.

 

[Flareside302]

That just means it's doing its job.. As long as using a quality oil, I would follow the OLM.

You can always do a used oil analysis to confirm if it's safe to go that far, but I have no doubt it should be..

 

[gregk24]

Just like others have said, its just doing its just cleaning up crud. I dont trust the GM OLM, our Uplander has one and after 3000 miles of 1/2 mile trips it was showing 86% left, oil came out like pitch and smelled pretty strong.

 

[dparm]

Visual inspection is not that useful unless there's something like coolant contaminating it. Oil turns black with use.

 

[y_p_w]

I've changed the oil in several cars. The color of the oil might not be a great indicator of its condition depending on the additive package. Some cars are also very different. If there's a quart of oil remaining in the engine, then it will lighten after a change but can still look dark.

I remember I'd change the oil on my parents' 2001 Camry V6. When it was fairly new the oil could be changed at 4000-5000 miles and the dipstick test said the oil barely darkened. After an oil change it looked brand new. Over time it started to look darker, but that's not much of a test of anything. And that engine is a notorious sludge monster. Now my dad's '96 Buick Regal Custom would turn the oil almost jet black in a few hundred miles. I helped with the maintenance and almost always used AC filters because they were cheap and specified in the OM.

Now I'm starting to run mostly highway miles and after an oil change the oil is not pale like new oil. It doesn't matter as long as the oil is doing its job.

 

[stchman]

Unless oil has the consistency of sticky tar on the dipstick, you cannot go by looks. Change the oil when the OLM tells you to.