Oil change

What’s your preference? Let the car sit overnight and then drain cold oil first thing in the morning (all oil has drained down completely overnight) OR warm it up and drain warm oil. This is of course, for an oil and filter change. I prefer to do the “let it sit overnight and drain it next morning” thing, to have all of the oil drain down to the oilpan and get it all out next day. Preference? Rocketman

When I used to change my own oil using ramps, I would have a warmed up engine, drive it on the ramps, let it sit for a few minutes and then drain the oil and take off the filter. When the oil drain was down to the occasional drip, I would put the plug back in as well as a new filter.

Our current cars wont go on the ramps, so I have others do the oil change for me. In all cases I make sure the engine is thorouhgly warmed up.

Many Jiffy type lube places will barely drain the oil out before putting the plug back in to get you out of there as quickly as possible.

I prefer the warm oil approach. Well, preferred, I have it done now. But I also think it makes no real difference, the old oil isn’t going to hurt anything, just getting out the great majority of it is the important thing.

Cold oil is nicer on the hands but hot or atleast warm will drain better IMO

Warm oil. Pull the drain pug and go do something else for a while so it all drains out. Put the plug back, unscrew the filter a couple of turns, let drain, a couple turns more, let drain, remove.

Warm oil.

Warming the oil up gets the contaminates back into suspension so it drains out with the oil.

Letting the oil sit overnight allows these contaminates to settle in the oil pan, so when the cold oil is drained most of these contaminates aren’t removed.


If you’re going to let your car sit overnight, why wouldn’t you take out the plug at night and let the oil drain until morning?


No disrepect intended . . .

But I think your idea is not good, and this is why

OP’s son, daughter, wife, etc. will grab the keys in the morning, start up the car and head off to church, the corner grocery store, etc.

And if that person that starts the car has the radio on, they won’t hear the engine’s protesting

And if they’ve not yet fully woken up, they won’t see the red oil pressure warning symbol

I’m sure this scenario has played out a few times, somewhere, some time

I think the driving off in the morning is an unlikely scenario if the car is up on ramps.

I did once have a car disabled in the drive and just taped a note across the driver’s side door that the car couldn’t be used.

I usually do the warm it up and then change it method. I also let it drip a long time as I often do other things with the car during the oil change. So it drips while I’m doing other things.

Cars, airplanes; you never want to leave something half finished. A spare car is no good unless it runs. You drain it and wait until the flow is almost reduced to droplets and you screw the plug back in and tighten it. Deal with the filter and refill the oil. Don’t over-process. Nobody wins at that kind of game.


OP did not mention putting the car on ramps . . . you did

In any case, OP himself might be the one to start the car the next morning, with an empty crankcase, because he forgot the oil was drained

I’m sure it’s happened, somewhere, some time . . . I’ve even seen some professionals make that mistake

“In any case, OP himself might be the one to start the car the next morning, with an empty crankcase, because he forgot the oil was drained”

There have been occasions when I had enough time to drain the oil from my snowblower, but did not have the time or the inclination to find the right oil (in the dark) and refill it before going to bed.

Just the possibility that I might forget has caused me to put a sign on the controls of my snowblower saying NO OIL, just so that I don’t have a brain fart and attempt to start it the next morning if there was an unexpected snow storm.

If it can happen, it will happen…at some point…

In 25 years of doing this I have never left a drain plug loose and never forgotten to put oil in an engine. I have however forgotten to drain the oil. Changed the filter, lowered the car, put 5 quarts in and wondered “Hmm, don’t remember it running this rough when I drove it in.”

I prefer oil to be warm when drained. For one thing you get it done faster.

I think OP is saying to park the car and let the oil drain from the valve area back to the oil pan overnight. He’s not saying to remove the drain plug and let the oil drain out of the engine overnight. So the OP’s method, if somebody started the car before the oil change got started in the morning, the car would still have oil.

When I change the oil I warm up the engine for 5 minutes first, before starting the drain-out process. But I doubt there is much benefit to doing it that way. Draining out from a cold engine would work just as well I expect. The warm way, it is just the way my dad taught me is all.

Come to think about it, I don’t do it exactly the way my dad taught me. Maybe it was something about his depression-era thinking, he had some unusual ideas about car care, but after draining the oil out he’d put the drain plug back in and pour diesel fuel into the crank-case, idle the engine for 5 minutes, then drain it out again. His idea was the diesel fuel treatment would clean the engine innards better. I seriously doubt it did any good. But it didn’t seem to do any harm either, at least to his 1964 F100 truck.

Hey George,

Here’s why you run the engine for a few minutes before changing the oil.


I do it cold in the morning.
The drain plug is at the lowest point of the pan (at least every one I’ve seen), so any sediment will collect right there and be the first thing to come out.

I like to do it first thing in the morning in warm weather and just after the engine reaches operating temp in the winter. Since my car is garaged, it always gets started at least to pull the car out and up onto the ramps.

If you park anywhere but a garage, I would be concerned that the street (driveway) is a little slanted. If the car is parked the wrong direction, the oil draining into the pan might flow forward rather than to the plug.

I can not leave the oil draining overnight. Too many things to go wrong, a few to mention would be wife (!!), Earthquake (CA), fire, other emergencies. Normally I have to start the car and pull it in the garage bay that I use for my work, so the oil gets circulated, but in the CA desert, not much needed to warm up the car and I hate sweating even more than I do.