Can a GDI engine blacken oil in just 25 miles? (See pics)

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Jul 27, 2006
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I get free oil changes from my dealer for my 2019 Altima, which has a PR25DD GDI engine. After getting the oil changed yesterday, I drove 25 miles home and checked the dipstick. To my surprise the oil appeared black, so I pumped some out through the dipstick pipe and it is super dark, looks black in the bottle but very deep red in thin film, sort of like Coca Cola. I pulled two more 8 ounce samples just to be sure everything was flushed and it is just as dark. Even with a bright flashlight behind my sample, no light is visible through it.

I called the dealer and asked them to check with the mechanic who did the oil change to see if he may have forgotten to change the oil as I had other work done as well. The mechanic distinctly remembered changing the oil and filter, so I asked them to check their bulk tank. They sent me a photo of a sample from the bulk tank and it is golden. The dealer offered to change the oil again, which I plan to do.

The oil is a 0W-20 which they tell me is a full synthetic from Mobil, although the paperwork shows it as Nissan Genuine Oil (could be both). I did an 5,000 mile UOA on the last change at 50,000 miles, and while about 10% lighter than expected in additives and viscosity, it was still reasonably consistent with API SPs oils and the wear metals were excellent.

I know GDI engines generate some soot, but is it possible for a GDI engine to blacken the oil this much in just 25 miles of highway driving?

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T25_9277bs5.webp
 
I doubt it was changed. A similar story, and why I have a feeling the oil wasn't changed. Many years ago I had warranty work done and the dealer had a tire rotation special for a price that was too good to pass on, especially since I was due for a tire rotation. I don't trust dealers so I marked the tires. I picked the truck up and checked, much to my disappointment the tires weren't rotated. I asked the service manager if they forgot to rotate the tires. He checked with the mechanic who swore up and down he rotated the tires. When I showed him and the service manager how I marked the tires, they were not happy campers. At that point they offered to rotate the tires. I passed for fear of them retaliating and messing up my van. I'm not saying this is going to happen to you, but looking at that oil I have my doubts it was changed. I would watch like a hawk if you take them up on changing the oil.
 
My GDI Focus definitely darkens the oil faster than my non GDI Escape with engines from the same engine family (Duratecs which are Mazda MZR derived). The Focus usually starts to darken the oil after about 2 to 2.5K miles but certainly not after 25 miles. I think your dealer is either mistaken or worse.
 
There is something not right here. Following the several million miles I have driven and did my changes myself I've never seen mine be so black like this with only a few miles on it.
 
There is always some residual oil left in an engine after an oil drain.
It is possible that the residual oil diluted the fresh oil by some degree, causing the fluid to be darker.
That being said, it should be a repeatable occurrence; try it a few times and see if it happens each time.
 
Great they offered to do it again (or for the first time). Looks way too dark for 25 miles, I would go with not changed or put drain plug back in way too early. My brothers Titan w/ the DI 5.6 darkens oil quite quickly but nothing like that.

Last OC on our CX-9 was done at WM. I can tell they changed it but I believe did not let it drain completely as oil was darker than expected after 200 miles. I always do my own stuff but life happened. A good reminder that if you want it done the best way, do it yourself.
 
There is always some residual oil left in an engine after an oil drain.
It is possible that the residual oil diluted the fresh oil by some degree, causing the fluid to be darker.
That being said, it should be a repeatable occurrence; try it a few times and see if it happens each time.

Exactly so. Some engines in cars (including pickups) will hold as much as a quart in the pan plus elsewhere, making it impossible to ever get an oil change that looks new barring just dumping a few gallons straight through from filler to open drain bolt (and maybe not even then).
 
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