Oil Change : Hot, Cold or Warm, or does it matter?

[DEWFPO]

There are pros and cons to changing your oil when it Hot, or when it's Cold or somewhere in between.

Is the any data to show more contaminants are removed from the engine when the oil change is performed when the oil is Hot? or Cold? or Warm?

Sometimes my only real option is to change it when an engine and oil are cold. Is that better or worse than doing it cold or warm?

I know many have opinions but I wonder if any studies have been done or is it a no brainer?

Thoughts?

DEWFPO

 

[oggb]

Only problem to changing it hot is that the metal bits that tend to be around your oil filer / drain plug also tend to be very hot.

It takes longer to drain when it's cold, especially if you use something like 15w-40.

It probably makes very little difference in the end.

 

[casperfun]

Doesn't matter. As long as you change your oil, that supercedes all other variables in my opinion.

 

[spasm3]

I could see an advantage to changing the oil cold , if you put it on ramps the night before, and change the next morning. You might get more oil out that had time to drain down from the cyl heads overnight. It will take longer to drain out the pan though. I change mine hot, or warm.

 

[Mr Nice]

It doesn't matter

 

[Virtuoso]

The fact that you are changing your oil alone is 99.9% of the worry I think.

As long as you allow it to drain completely you are good to go.

I do like to warm up the engine beforehand during the winter. Gives me something heated to wrap my hands around.

 

[Jim_Beverlin]

I run Amsoil in my vehicles and change once per year. I always change when the oil is hot and make certain I have sufficient time for a thorough drain. I pay attention to how the oil drains. For example, my Jeep Liberty drains from the back of the pan and gets a thorough drain on ramps. Not so with my Ford Explorer Sport Trac. The Ford drains from the side so I have drain it off of the ramps to get a complete drain. I do the oil changes in good weather. I will start the drain and mow the grass and come back about 3 hours later and finish up. Time consuming but I am reasonably confident that most of the oil is out of the engine.

 

[oilboy123]

I have been changing oil for several decades and have no proof than any of the three are the best. Main thing is changing it. I would say best hot, next best warm, and last cold.

 

[casperfun]

Originally Posted By: oilboy123
I have been changing oil for several decades and have no proof than any of the three are the best. Main thing is changing it. I would say best hot, next best warm, and last cold.


several decades? are you sure your not oilgrandpa123?

I'm an old fartt too.

 

[beast3300]

I prefer the hotter the better (at least on the draining the pan part). There is probally no perfect answer.

 

[JHZR2]

hot and often used to be the word.

Ive never measured volumes for hot vs cold, or done a pan drop to see efficacy...

It does seem like it comes slower though doing it cold. Id prefer to have everthing agitated myself.

But doing it cold is better than not doing it...

 

[subiedriver]

I drain my oil "warm", give it about an hour after shutdown, then drain it. For me, the oil gets drained after a 40 mile run down the highway coming home from work, pretty much ideal.

 

[HTSS_TR]

Since I use an oil extractor I prefer doing it warm, I would wait about 15-20 minutes after a good highway drive before I extract the oil with Mityvac. I use this waiting time to prepare and change the cartridge oil filter on top of the engine.

 

[dwendt44]

Ignoring the old wives tales about draining oil 'hot', I see only one advantage to changing 'hot'.
The bearings and cylinder walls still have a nice coating of oil present for start up after the change.

I've done both; usually do it 'warm' as above.

 

[FZ1]

I get it hot and let the dealer change it.

 

[Errtt]

I used to drain it hot. Now I go to an indy and pick it up later in the afternoon.

 

[oilboy123]

Originally Posted By: casperfun
Originally Posted By: oilboy123
I have been changing oil for several decades and have no proof than any of the three are the best. Main thing is changing it. I would say best hot, next best warm, and last cold.


several decades? are you sure your not oilgrandpa123?

I'm an old fartt too.

When I turn 50 next year I'll change it to oilgramp

 

[Rick in PA]

Originally Posted By: oilboy123
I have been changing oil for several decades and have no proof than any of the three are the best. Main thing is changing it. I would say best hot, next best warm, and last cold.


"several decades"? Can you be a little more specific there?

I've been oil changing for a few decades, myself. (Come to think of it, that's a lot of oil changes!)

I'd agree with the above, but my personal favorite is hot.

When I was young, my brother helped me rebuild a slant six for a '65 Dodge Dart. We loaded the motor with SAE30 and ran it in for about 15 minutes at 2,000 RPM. Then we dumped the oil right away. Let me tell you, for 30 weight oil, it just gushed out of the crankcase. It was good and hot. I liked the way it drained, excellent flow, I was confident that it removed all the contaminants possible.

I'll liken it to apple cider. (I happen to be drinking some right now). The bottle always says to "shake well", that way you get all the "good stuff" in suspension. I believe it's the same with a crankcase. I like to buzz the engine up and hold it at a couple thousand RPMs for a few minutes just before I drain it. If the drain plug is too hot, I have a piece of rubber heater hose that presses over the hex to use as a handle. Works most of the time.

All that said, the main thing is change it. The style is a bit of a matter of preference. I've done a few lukewarm changes, no problem.

There's your ramble for the day.

Have a good holiday weekend,
Rick

 

[DEWFPO]

Thanks for the input folks.

It sounds like it doesn't matter much what the oil temp is when drained but, if given a choice, hot would be most popular method.

DEWFPO

 

[AMC]

Originally Posted By: oilboy123


I'll liken it to apple cider. (I happen to be drinking some right now). The bottle always says to "shake well", that way you get all the "good stuff" in suspension. I believe it's the same with a crankcase. I like to buzz the engine up and hold it at a couple thousand RPMs for a few minutes just before I drain it.



Wouldn't that mean that you would want to change the oil cold so all the "good stuff" is on the bottom and gets drained out of the engine first? It would seem you don't want all the particles and contaminants (good stuff) to be distributed back up into the engine so they can't be drained out completely.
I think the OP has a very good question here.