Oil Change - Arguments against "cold" oil change?

[Emission]

I've been changing oil for twenty years. It's the same routine each time... drive the car to heat the oil, jack the car up, open the drain plug and avoid the scalding mess as it drips everywhere.

Here's what I've heard:

WARM OIL FLOWS BETTER - Logic says warm oil flows better so you can better get "every last drop" out of the block when doing the change. In the 911, there has got to be more than a gallon tied up in the oil lines and cooler in the front fender... so I'm not so worried about those "drops" hanging around. Hmmm.... I'm also running synthetic, so mine flows pretty well cold anyway.

WARM OIL HAS LESS MOISTURE IN IT - Makes sense, as water evaporates out of the hot oil. But, my car is garaged and never runs short trips - so moisture shouldn't be an issue in my car. My last trip (last week), was 40+ miles.

My car is in the garage (cold), and I want to change the oil today. I don't have time for a 20 minute sprint to get everything hot... So, my question remains. Why can't I change oil cold? Does anyone have a good argument against it?

[sundaypunch]

I have no problem changing the oil cold on occasion. I typically will do it warm since I think debris is more likely to come out.

[svandamme]

you can perfectly do it cold
it just works better warm
that's it.

[vash]

i do mine cold. the slightly thicker oil doesnt ever overflow my oil pan. IMO if you stay regular with the changes, you are leap and bounds ahead of the non regulars anyways.

[Jim Sims]

A cold oil change is better than no oil change; it just takes longer for cold oil to run out so for a given amount of "drip time" you'll change out less of the oil. No big deal. Jim

[RoninLB]

to my understanding hot oil has all the impurities still in suspension.

[Emission]

Originally posted by RoninLB
to my understanding hot oil has all the impurities still in suspension.

Good point.

I'd think (hope) the larger particles would be captured by the filter, but the small stuff could fall out of the cold oil and be stuck on the bottom of the lines and pan until it warms (flows) again.

Anyone to second that?

[svandamme]

well , if you guys are that concerned... i suggest dismanteling all the lines for a thourough cleaning whenever you change the oil... better yet, replace them... just to be absolutely sure...

[RoninLB]

Originally posted by svandamme
well , if you guys are that concerned... ...

I missed your answer to the man's issue

[vash]

"the best solution to pollution is dilution." that is what my waste water professor told me. it applies here too.

[gerard vaglio]

The fact that you spend time thinking about this means your a good person.

[svandamme]

Originally posted by RoninLB
I missed your answer to the man's issue

my answer is : ain't worth worrying about it...
if it's cold and you don't feel like warming it up... then don't warm it up. if you feel like worrying , then feel free to warm it up...
warming up is probably better, but the engine isn't gonna explode 10 minutes after you do a cold oil change either...

[Vintage911Racer]

Since you can't get all the oil out of the cooler or the lines to the cooler, does it really matter all that much? Since Mine is a race car, I always change it cold. However I change it before every race.

[jmohn]

Originally posted by sundaypunch
I have no problem changing the oil cold on occasion. I typically will do it warm since I think debris is more likely to come out.

Total agreement.

Jerry M
'78 SC