What about all the other times the car gets started after sitting all night?
Hot or Cold oil change?
- Thread starter SR5
- Start date
I used to change scalding hot oil but, with the modern detergent and lighter oils, I see no reason to change oil supper hot. I warm my engine up by driving on my ramps (~ 3 minutes) and change it warm. Drains just quick and completly that way. Ed
I drive it around for about 20 minutes and then do oil change. Or if I’m coming back from a long drive I will let it sit for about an hour and then do the oil change. Not super hot but not sitting all night.
Like others have mentioned, as long as you are changing the oil it doesn’t matter
Like others have mentioned, as long as you are changing the oil it doesn’t matter
The two best methods I have seen in this thread where positive results (more oil coming out) are:
1. Run the engine hard and long to get it extremely hot.
a. Drain immediately
b. Let it sit over night and drain cold over a few hours so every bit drips out
1. Run the engine hard and long to get it extremely hot.
a. Drain immediately
b. Let it sit over night and drain cold over a few hours so every bit drips out
- Joined
- May 28, 2014
- Messages
- 2,262
You know,it's a habit of mine now to do a oil change later in the day so I can just walk away from it ,let it drain all night and finish the job the next day.
I change my oils in the summer time and drain when the car is cold. Reduces the risk of me being potentially burned. There’s no substitute for safety.
Also, you have oils with pour points of -40 does warming the engine up so it evacuates faster really make that much of a difference? No. I can wait 5 - 10 mins extra. That being said either way is fine. For those that say when it’s heated the contaminants are in suspension, isn’t the oil filters job to trap said contaminants and keep them to a minuscule amount? Just how big is the difference in contaminants being drained for a hot vs cold? Any legitimate quantitative data on this? This is a serious question. Don’t mean to sound sarcastic. Cheers.
Also, you have oils with pour points of -40 does warming the engine up so it evacuates faster really make that much of a difference? No. I can wait 5 - 10 mins extra. That being said either way is fine. For those that say when it’s heated the contaminants are in suspension, isn’t the oil filters job to trap said contaminants and keep them to a minuscule amount? Just how big is the difference in contaminants being drained for a hot vs cold? Any legitimate quantitative data on this? This is a serious question. Don’t mean to sound sarcastic. Cheers.
From a practicality standpoint I try to go for "warm" but not burning hot, just to make my life easier when working on the car. So basically, cold start, drive it around the block for 5-10 minutes or so, then drain it. If the car's been super hot running on the highway for an hour it just gets too hot when you're draining out the oil for your hands and touching the oil pan, filter housing, valve cover, etc, etc.
Yes some parts of the dirty oil will *start* to settle out after sitting for hours, but I am pretty sure you won't get a caked layer of sediment on the bottom of the oil pan. Any engine that gets regular maintenance using modern oils will be pretty clean inside. So changing oil *hot* is not about sediment left behind or anything like that. For me, draining the oil while hot means more oil is coming out. I'm one of those people who refuses to let it drain more than around 6-8 minutes. I install the drain plug after it starts dripping. Seriously, how much more oil is coming out by letting it drip overnight... 5 ounces? 10 ounces? A considerable quantity of used oil stays inside the engine no matter what, so I don't see any real-world benefit to be had here. Just get it done. There's a difference between good enough and going overboard. Oil changes aren't supposed to take hours and aren't supposed to be agonized over. Regular maintenance is the most important thing here.
EDIT: sorry I don't have any quantitative data for you LOL
Once I left the oil drain overnight and it took 1/2 quart more than my usual oil changes.
The only time I change it hot is if I need to--otherwise drive up on the ramps--or drain a high clearance vehicle cold in moderate ambient temps. I always change the oil before winter and again in the spring when it warms up. Use an EP oil and filter if needed for the mileage interval during the winter months. So as stated many times on this thread, good oil will flow out quickly in moderate to warm temps. Where is the advantage of changing the oil hot? Any particulates of concern will be filtered before the engine is shut off--so where are the particulates coming from that will settle out? If the particulates are only in the hot oil, well then they are spread all through your engine and will cling to the engine parts till the hot oil all drains back down an hour later. So even with hot oil you still have fine particulates left behind unless you drain your oil for about an hour.
You will get more oil out when it is in the pan then when it is clinging to hot engine parts. Good oil should not separate--its not like homemade chocolate milk that you need to shake. Do you heat your oil and shake it in the bottle before pouring it into your engine so you get all the good additives lying on the bottom?
Changing oil hot had its day--but that day has passed and there are more benefits in changing it when it is all in the pan because you will get more old oil out (unless you want to make a long project out of changing your oil waiting for the hot oil to drain down). In reality I don't think it will make any discernable difference in engine longevity whether it's changed hot or cold, when changed in moderate or warm ambient temperatures.
You will get more oil out when it is in the pan then when it is clinging to hot engine parts. Good oil should not separate--its not like homemade chocolate milk that you need to shake. Do you heat your oil and shake it in the bottle before pouring it into your engine so you get all the good additives lying on the bottom?
Changing oil hot had its day--but that day has passed and there are more benefits in changing it when it is all in the pan because you will get more old oil out (unless you want to make a long project out of changing your oil waiting for the hot oil to drain down). In reality I don't think it will make any discernable difference in engine longevity whether it's changed hot or cold, when changed in moderate or warm ambient temperatures.
That's interesting: more than I would guess.
As someone who used to change vehicles mainly burning hot (some people got right off the highway driving for hours) and then cold enterprise rentals that set outside overnight and brought over from across the street for an oil change. The difference in draining between those vehicles was so huge that I never want to change oil cold again. I have a high pain tolerance (also do the dishes while water is still very hot). It may not make a difference, but when your goal is 500k miles plus, you do everything you can.
I have also done hot oil drains, and then leave it to drain overnight. Have done this on half a dozen vehicles, and they all take more oil than the service manual says for an oil & filter change. My Z06 also took 1/2 qt more, but I also lifted the back end up a foot to tilt the engine since the drain plug was on the front of the pan, which might have helped get more oil out.
One way to test how much more comes out if left to drain over night is to put a clean drain pan under the engine after the initial drain when it starts to drip. The volume in the 2nd clean drain pan will be the delta.
What was the quantifiable difference that would affect engine longevity?
I’ve done both and never had an oil related problem , does it matter ? Probably not do what makes you happy.
I don't need a quantifiable difference....if I can get more of the old oil out, instead of less....then why wouldn't I? I can't believe I'm even being asked questions like this. What is the point of this site anyway?
Sorry for getting short. To put it in perspective...I now get paid mileage to drive my own truck (which was basically a gift from my employer), trucks are like $60,000 now, I've never paid more than $1500 for any vehicle the past 17 years of my life (I'm 37 now). If I have to buy a newer truck I basically lose the biggest raise I ever got.
I'll be putting another 200k miles, hopefully more on this truck, as long as it doesn't get wrecked or something. I would rather hit 500k miles and wonder if I could have made it that long without bothering with so much attention to maintenance than be at 300k miles and lose the engine and wonder if I should have kept being so crazy about my maintenance.
I know not everyone else has the same lofty goals with their vehicles that I do, but if I'm working on their vehicles I feel morally obligated to be at least somewhat as anal with them as I am with my own cars. The reason they ask me to do it is because they know how particular I am with cars and they know I'll do a good job. Changing the oil hot to get a bit more of it out is just one small effort, in my opinion.
I'll be putting another 200k miles, hopefully more on this truck, as long as it doesn't get wrecked or something. I would rather hit 500k miles and wonder if I could have made it that long without bothering with so much attention to maintenance than be at 300k miles and lose the engine and wonder if I should have kept being so crazy about my maintenance.
I know not everyone else has the same lofty goals with their vehicles that I do, but if I'm working on their vehicles I feel morally obligated to be at least somewhat as anal with them as I am with my own cars. The reason they ask me to do it is because they know how particular I am with cars and they know I'll do a good job. Changing the oil hot to get a bit more of it out is just one small effort, in my opinion.
I like the way you think and will change my oil piping hot to get out every last bit, maybe even let it sit overnight too. Why not? I'll be sleeping.
Just don't burn yourself
put some rubber gloves on at least.I can see that you would get more oil out piping hot versus start it up and drive up the ramps and drain it. But my current vehicles (truck, SUV, Subarus) I can drain cold drain (in warm/moderate ambient temps) without putting them on the ramps and all the oil is already drained down into the pan and will all drain out. I can park the vehicles where I want to service them the next day.
Not trying to quibble over trivia--just saying there is another way to achieve the same results without changing it hot, specifically if working on higher clearance vehicles.
Not trying to quibble over trivia--just saying there is another way to achieve the same results without changing it hot, specifically if working on higher clearance vehicles.