Does oil that gets dirty quicker mean that the oil is doing a better job or worse job? If the oil stayed clean between changes, would it mean that all the contaminants are staying in the engine as sludge???

Seems to me that if the oil is dirty, contaminants are suspended in the oil, not on the inside of the engine. Am I all wet???

Thanks, Paul

 

lots of different opinions I am sure. Here's mine.

Oil can look dirty in three ways. 1)Normal combustion contamination or 2)extreme blowby or 3)sludge already in the engine.

I have had about 20? cars(trucks, vans) in my life so far and some have oil the color of honey at the end of each change even after 50,000 miles, and some have dirty oil from day one. I have never been able to figure out why some engines have "clean" oil and some "dirty", even the same engine and model etc assuming it is in good condition. Guess just manufacturing tolerances and how you drive.

"Dirty" oil is not necessarily bad. Like one advertisement says, the oil looks "dirty" because it is doing it's job and "capturing" the dirt in suspension so it can be drained or caught in the filter.

My opinion is as long as 1)You follow SAE and API specs for your engine and 2) You change regularly, and 3)Your engine is performing well and doesn't "Burn" oil, you are OK. There is another thread about changing oil every 10 miles or up to never. I stick to the manual recommendation on mine and use good oil and filters. I have had a few cars go almost to 200,000 before I got tired of them and none ever showed signs of unusual wear, even the truck I had that I drove with a hole in the pan for 20 miles before it froze up, that one ran another 130,000 after that fiasco. All with good oil.

Jim Henderson