Do you think it's better to change your oil while the car is still hot or are you better off letting the car sit for a day?

[ThreePedalPlow]

Maybe it doesn't matter being the oil filters have anti drain back valves. I was just curious what you guys recommend if anything. My car has been sitting for a couple days due to bad weather.

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[Dena]

Hot is better because the partials may still be suspended in the oil. Also the oil will flow out of the engine better. Does it really make all that much difference? Probably not.

 

[erocker]

Doesn't matter in the slightest.

 

[highvoltage]

I always drain after car has been driven up to temp. Makes for easier drains.

 

[BrianJ77]

I always warm mine up a little to thin the oil and I like knowing I have oil on the internals of the engine for that dry filter start. Mostly it's just my personal preference and makes me feel better about that 3-5 seconds that it takes the oil to get to the bearings, etc.

 

[Zig]

I always warm mine up a little to thin the oil and I like knowing I have oil on the internals of the engine for that dry filter start. Mostly it's just my personal preference and makes me feel better about that 3-5 seconds that it takes the oil to get to the bearings, etc.

In this vein.

warm oil flows easier than cold oil. In my experience oil filters usually break free easier once warmed, although I will admit I haven’t experienced the joy with ours yet.

Thoughts on prefilling the filter?

 

[Skye]

I feel it drains more completely when at a warm temperature. The oil flows better. Any particles suspended in the oil are more likely to make the move and join the rest of the flow.

The S550 filter goes in at a 45-degree angle. While I couldn't completely pre-fill it, I got it about half full, priming it. I poured some in, waited for that to settle, put some more in, then put the filter on.

Any of the points we're discussing are steps towards goodness. You can't prove in makes things better, but it seems to make sense. And doesn't hurt anything.

 

[BrianJ77]

I also prefill the filter, but I've been told it doesn't make a difference by a Ford technician. I have also been told not to lube the gasket either as it can cause the filter to back off of the newer engines. Two things I've done since I got my first car at 17. Hard habits to break.

 

[Rdw401]

Warm is best as it thins the oil and it flows better and faster.

 

[highvoltage]

I have never prefilled a filter. But i always lube the gasket

 

[LCDRChemEng]

Hot oil flows faster, but getting scalded by hot oil - not fun. I'm getting a Valvomax or similar plug that allows draining through a little hose to avoid this issue.

I've always lubed the filter gasket, nothing worse than an old filter that just...wont...budge!

Never heard about pre-filling the filter though. Are we sure refilling the oil reservoir will not refill the filter also prior to starting the engine?

 

[Zig]

Never heard about pre-filling the filter though. Are we sure refilling the oil reservoir will not refill the filter also prior to starting the engine?

Something comforting about watching it absorb into the filter…

 

[Stratman397]

Maybe it doesn't matter being the oil filters have anti drain back valves. I was just curious what you guys recommend if anything. My car has been sitting for a couple days due to bad weather.

My hubby always drives the car first before he changes oil

 

[MAT1955]

@ThreePedalPlow ..... always bring it to the dealer hot. Some dealerships will wait a bit if the oil is super hot so the techs don't get burned. Uncle worked for Shell oil as a chemist. There is no doubt and I mean NO doubt. When the oil is first heated to operating temperature, the many particulates and chemicals (especially water vapors and acids) are gathered, placed in suspension and removed. The oil also drains from internal components significantly better drawing detritus away. This is not opinion but pure physics and chemistry in action. A cold oil change imo would be worth less than 60% of the desired outcome and I'm being very charitable. Myself, I wouldn't even bother changing cold oil as I would deem it as essentially worthless. I'd a wait until I could ensure it was done right after running to operating temp and cooling down no more than very, very warm. I warn my tech and I tip him. He wears gloves, prefills the oil filter (twice) and buys a few beers with my tips. We are both happy. My vehicles (automotive and marine, naturally aspirated and supercharged) have always prospered and I have people asking to buy them when I go to sell them. This is one of the easiest things to get right with your car that has immense impact.

 

[Farmer Fran]

Well, i usually do mine Saturday or Sunday morning cold. I guess my engine will die soon.

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