Originally Posted by billt460
Originally Posted by SR5
I was always told to do an oil change when the oil was hot or warm, I think the logic was that more contaminants were in solution and the oil drained out faster. But now I think on that logic, if the oil needs heat to keep contaminants in solution then I should have changed the oil long ago and I already have an engine full of sludge and varnish. With modern thin synthetic oils used over reasonable intervals, does it make any difference if you change the oil hot or cold ?
You could argue it shouldn't.... But why? If you have particulate matter in a liquid, mixing that liquid right before you drain it from whatever container is going to leave less of it at the bottom. Add to that being hot makes ANY motor oil, regardless of it's viscosity, drain faster and more completely. Especially off of hot engine parts, of which there are many. Which helps contribute to all of this in a positive manner.
You have 2 choices when changing oil. Do it hot or cold. I can't see any possible advantage to doing it cold, other than you won't possibly burn your hands. And most everyone who takes their vehicle in for an oil change, has it done hot. As do most people who do their own. So what percentage does that leave of cars that have cold oil changes performed? It has to be an all but insignificant number.
You might say this is one case where, "running with the sheep" won't get you slaughtered.
I agree. I'm going to stick with the way I was taught. Drive the vehicle, let it cool while I gather my tools and change the oil warm to hot. I have a nice pair of oil proof rubber gloves that protect me against burns if needed.