Draining excess oil tomorrow and wondering after leaving the car overnight will any additives within the oil separate sinking to the bottom of the sump?

If so how long of a drive should I take it for to get things mixed up?

I would also like to have an idea how much oil is pumped around the engine lets say in one minute running time?

1 Answer 1


Run the car for about 5-10 minutes to get it warmed up, then drain what you are going to if you are dumping it out the bottom. Getting it warmed up a little bit will allow the oil to drop out pretty quick. Wear gloves (nitrile) if available. The oil will flow fast, so pay attention to what you're doing or you'll dump out too much. If you dump your oil into a clean container, you could possibly put some back if you dump out too much.

As far as how much oil goes through an engine in a period of time, it all depends on what the car is, which engine is in it, what mods are done to the car, how many miles are on the car, what oil is in the car (synthetic/dyno/weight), when the last time the oil was changed, how fast is the engine spinning at any given time, etc, etc, etc. In other words, there are just too many variables to give you a good answer.

  • Good answer very informative thank you :) as I am running the car up to get the additives mixed up does an oil pump curculate more than 5 litres a minute? Or much much more? To keep all components lubricated I imagine it has to pump a fair bit?
    – ceefax12
    Dec 22, 2015 at 2:41
  • 1
    I wouldn't think it would be more than 5L per minute, but really, it's hard to say. Dec 22, 2015 at 3:04
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    Oil is designed so that the additives stay in suspension. The one exception is detergents. They work by combining with contaminates. The design is that even this stuff stays suspended, but when the contaminate load exceeds the limit of available detergent it starts to precipitate out and collect in the oil pan and stick to the inside of the engine. Dec 22, 2015 at 7:07
  • hmmm interesting so even after the engine has reached oparating temprature many times and driven long distance the only separating that should occure is the "cleaning agents" and when they do seprate the become useless anyway?
    – ceefax12
    Dec 22, 2015 at 19:55
  • If this is true I should be able to drain out what I need without having effect on the engines lubrication.
    – ceefax12
    Dec 22, 2015 at 20:06

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