hi all

I have been hearing overtime that when you go to change your oil, when you drain it, the oil should be as clean or NEAR as clean when you put it in 3,000 miles ago or whatever. Now of all the oil changes I did when i was in my vocational school , every car and truck with about 3000 to 150,000 miles the oil was as black as it could be. My sisters b/f has a 1986 Toyota p/u truck with about 158,000 miles on it and I helped him changed his oil and the oil was a nice dk. brown color. He ran the truck about 3700 miles before changing his oil and he uses reg oil too w/o flushes. Now should the oil be black or should it be clean when you drain it, or at least somewhat clean when you drain it???????????????

 

As oil circulates thru an engine, it will pick up all sorts of contaminants and impurities from piston blow by, gasoline, carbon, and so on. The oil filter is supposed to get the big pieces but, the longer you go between oil changes, the dirtier the oil becomes and the darker it gets. Heat and additive depletion may also contribute to an oil changing color over time.

I have found that synthetic oils, when first added, will become very dirty initially, as systhetics seem to clean some of the gook out of an engine. After the second or third changes, synthetics seem to run somewhat cleaner than dino oils.

That's my take on it and my experience with synthetics.

 

Color of the oil is not an indicator of how well the oil is performing.

You can have a light colored oil that is not staying in grade, which could be causing wear, you would think all is well.

Also you could have a really dark oil that is perfoming really well, it might just have more contaminants suspended. Or in some cases it could have additives in it that cause it to become dark.

If you are questioning weather the oil is suitable I would suggest doing an oil analysis. This is the only true way to tell.

(PS) after 10,000 on my current oil, it is dark but by no means black and thick.

Though on my Jetta TDI the oil turns totally black in less than 500 miles. go figure.

 

In all honesty, I've never seen anyone drain there oil and the oil be as clean or near as clean as when it was put in. Actually, I've never seen used oil that was anywhere near the same color as it was before it was used. If it was, I'd be concerned the oil isn't doing it's job...

 

ok thank you everyone for the replies and info. So maybe the oil in my sisters b/f truck is maybe not doing it's job but then again it might be too. Anyone else wants to say something be my guest. And Jaymz I WANT YOUR GREEN TRUCK, NOW!!!!!!!!!! LOL!!!!

 

I like the grren truck, too, and it has been a damn fine truck! Just rolled over 100,000 miles!

But, after you buy a Lightning, everything else is pretty mundane and boring.

 

Most Oil contains a detergent. The purpose is to clean your engine of contaminants, debris etc. Ever washed dishes with diswashing detergent? The water gets dirty eh? Oil gets dirty. The older and engine with more contaminants, the dirtier it gets and the quicker. Changing your oil every 3,000 or so miles just ensures that you are flushing the contaminants regularly AND your oil is in good functioning order.

 

I checked the oil in my brothers car (Geo Prizm) at 109,000 miles with 3,000 miles on the oil. It was as clean and yellow looking as the day it was poured out of the bottle. I have never seen oil stay anywhere near that clean before or since. BTW, he lost the car in the divorce but the last he heard it was over 170,000 miles.