Basic question - why does oil get black so early?

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I tried searching and believe it or not I couldn't find a thread on this - although I know it must get asked a lot For a new car with a new filter and new oil... why does the oil generally turn black by 3K miles. I realize some dirt and combustion byproducts get introduced... but black??? I could understand if the color went from amber to light brown but I am surprised just how dirty oil gets. Thanks for your help P.S. Can someone point me to threads that discuss this?
 
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Even after a 10,000 mile OCI my oil never gets black.Just tuns to a nice amber color.
 
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Mine never turns black after 3,000 miles. I've only had that happen in one vehicle I maintain, a 2001 Daewoo Leganza. I still don't know why, but it's running fine and I just change it every 3,000 miles to be on the safe side.
 
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Does depend on the oil. In my Saturn, Castrol GTX always got dirtier, faster. The Formula Shell I've run 4 or 5 times and its always stayed fairly clean throughout the OCI.
 
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Many factors play into how the color of oil changes during an OCI. And for the most part, they have little to do with how the oil is holding up. My Camry Hybrid has barely darkened the experimental fill of GC that's been in it for almost 3500 miles. The last fill, PP 0w-20 darkened to a mid-brown within a thousand miles. My wife's 3.5L Avalon seems to quickly darken everything I feed it, Havoline, GC, and now PP 5w-20. Relax and don't worry about it. Remember, diesels turn their oil sooty jet black almost immediately, despite the oil having many thousands of miles of life left in it.
 
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Do some oils hold by-products better? I`ve noticed different oils turn different colors: RP-brown M1-flourescent amber Valvoline-flourescent amber Pennzoil yb-stays the clearest of them all
 
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black oil means that its doing its job! and 3000 miles is a fairly long time on an oil... at least as far as it staying "clean"
 
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 Originally Posted By: ekpolk
The last fill, PP 0w-20 darkened to a mid-brown within a thousand miles. .
Where do you buy PP 0w-20 ?
 
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 Originally Posted By: tomcat27
black oil means that its doing its job!
Ya. If my oil didn't turn dark I'd be worried.
 
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 Originally Posted By: river_rat
 Originally Posted By: tomcat27
black oil means that its doing its job!
Ya. If my oil didn't turn dark I'd be worried.
Like I already said my oil never turns black. 31 years of amber colored oil. My sons Ranger has 330,000 miles on M1 and to this day it just stays amber. 10,000 OCI.
 
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 Originally Posted By: ekpolk
Many factors play into how the color of oil changes during an OCI. And for the most part, they have little to do with how the oil is holding up. My Camry Hybrid has barely darkened the experimental fill of GC that's been in it for almost 3500 miles. The last fill, PP 0w-20 darkened to a mid-brown within a thousand miles. My wife's 3.5L Avalon seems to quickly darken everything I feed it, Havoline, GC, and now PP 5w-20. Relax and don't worry about it. Remember, diesels turn their oil sooty jet black almost immediately, despite the oil having many thousands of miles of life left in it.
I'll + one on the diesel part. Every diesel I've ever changed oil on regardless of how new the oil was black. Even just after a start to fill the filter and recheck the stick.
 
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After changing oil on cars for over 35 years now, I've never seen "black" oil. I've seen some dark colored dirty oil though. I never worked on a diesel engine, so I can't comment about them.
 
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Have a '97 Geo Metro with almost 200,000 miles on it and the oil still stays amber till OCI at 5000 miles with Valvoline 10W/30 HM. I will say our new car doesn't get quite so dark but it has very little milage.
 
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 Originally Posted By: DeeAgeaux
 Originally Posted By: ekpolk
The last fill, PP 0w-20 darkened to a mid-brown within a thousand miles. .
Where do you buy PP 0w-20 ?
I've never seen it on a retail shelf. I ordered four cases of it (six qts per case) from Oilstore or Oilshop -- I forget the exact name. Google those and you'll find it pretty quick. Shipped right to my doorstep for a total cost of about what you'd pay at WM.
 
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 Originally Posted By: demarpaint
After changing oil on cars for over 35 years now, I've never seen "black" oil. I've seen some dark colored dirty oil though. I never worked on a diesel engine, so I can't comment about them.
Back in the early 80s, I had an 82 Jetta (got it used in 84, IIRC). Though it was a gasser, it would turn the GTX of the day ugly opaque jet black in a couple thousand miles. I've never seen a gasser do that since.
 
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 Originally Posted By: demarpaint
After changing oil on cars for over 35 years now, I've never seen "black" oil. I've seen some dark colored dirty oil though. I never worked on a diesel engine, so I can't comment about them.
Then you must not remember the old Arco Graphite oil. That stuff was practically black when you poured it in
 
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