Viscosity

[tiger862]

Can someone explain why extractor recommends warm engine before extraction of oil? We now have multi grade oils so they flow better when cold. 0w and 5w are winter numbers that allow better flow when cold compared to say 30 grade. If you heat engine first then the oil will no longer have the flow of winter grade therfore not flow as well. Am I missing something?

 

[Rand]

Can someone explain why extractor recommends warm engine before extraction of oil? We now have multi grade oils so they flow better when cold. 0w and 5w are winter numbers that allow better flow when cold compared to say 30 grade. If you heat engine first then the oil will no longer have the flow of winter grade therfore not flow as well. Am I missing something?

is this an april's fool joke late?

Assuming it isnt. flowing better when cold is relative.
Oil is still MUCH thicker when cold than hot.
analogy honey vs water.
m1 0w40 is 5x thicker at 104f vs 212f
is also 44x thicker at 32f vs 212f.

You want it warm to shorten the time it takes to suck out the old oil.
but not hot enough to soften the tubing.
100f-140f is what I aim for.. but 80f-170f or so is ok

 

[Cujet]

All oil gets markedly thinner when heated.

 

[kschachn]

All oil gets markedly thinner when heated.

Something that needs to be repeated again and again.

 

[4wheeldog]

It isn't just temperature. You want all the nasty bits to be suspended in the oil so they drain with it, not stay stuck to the bottom of the pan.

 

[BMW Dom]

facepalm

 

[tiger862]

I'll explain my question better. I understand oil flow at cold is thicker and warm is thinner however, all manufacturer of exchangers state warm cars up and even tehs repeat this statement. Will you damage the extractor by pulling cold oil? I used it to do all my lawn equipment without firing up and didn't have any problems. With oils today I don't see a problem with pulling cold oil, unless your worried about the minute you lose doing cold. On my vehicle being hot, I drove 25 miles this morning then replaced oil with engine cooled, again no problems. I like all oil drained back in the pan before changing oil. OEM 2 gallon extractor.

 

[facility1]

generally, what I do is warm the engine up to operating temp, then let the car sit for a hour or so, then use the extractor then as letting the oil or as much as possible settle down to the sump it will still be warm,. Oil no matter what the viscosity is more resistant to flow when cold.

 

[barryh]

Sure thinner oils are a a lot thinner when cold but they are still orders of magnitude thicker than when they are hot.

A viscosity vs temperature curve says it all.

 

[TurboZedd-R]

Forget all the graphs and hypothetical viscosity. Have you ever tried using an extractor on oil sitting at ambient temperature? If you haven't, it will take you forever to move a sump of oil. If oil is over 170F you can move a sump in 5 minutes.

 

[tiger862]

Forget all the graphs and hypothetical viscosity. Have you ever tried using an extractor on oil sitting at ambient temperature? If you haven't, it will take you forever to move a sump of oil. If oil is over 170F you can move a sump in 5 minutes.

I pull 2qts out of my lawnmower in less than 2 minutes. Mower hadn't been started in days. Same with pressure washer.

 

[kschachn]

I pull 2qts out of my lawnmower in less than 2 minutes. Mower hadn't been started in days. Same with pressure washer.

So wouldn’t that apply to your vehicle as well?

 

[TurboZedd-R]

I pull 2qts out of my lawnmower in less than 2 minutes. Mower hadn't been started in days. Same with pressure washer.

It seems like you are thinking the winter rating is being compromised and trying to defend using an extractor on cold oil. Simple physics shows things expand when heated. You do you my man

 

[4WD]

It’s the ID of the plastic tubing that has the impact - has to be small to go inside metal tubes - yet carry some wall thickness for collapse resistance … So, lower viscosity helps aid with these fixed points in design …
With hydraulics - ID has a far more reaching impact - but once fixed issues exist - you help where one can …

 

[tiger862]

So wouldn’t that apply to your vehicle as well?

That was my point. I don't see where it would hurt doing cold pulls. I think these extractor companies are referring to a single grade oil when they recommend run vehicles for 15 minutes to pull oil.

 

[tiger862]

It seems like you are thinking the winter rating is being compromised and trying to defend using an extractor on cold oil. Simple physics shows things expand when heated. You do you my man

I never said that winter rating was compromised. I simply said it didn't seem to make a difference rather pull cold or hot. Maybe a second longer but not much.