Wayne Smith

Good points for a one hour drain, but probably less so if you drain overnight. In either case the oil filter has to refill. I believe a residual film on the metal parts has a good retention time. I'm not sure about the chain tensioners and what happens during the drain period, but curious.

Ben Z

Unless you're in the southern hemisphere, this time of year the oil is always slightly warm.

Petza914

Another good point. Prefilling the oil filter before attaching it helps a lot with that loss of oil pressure on the first start afterwards. When I used to not prefill it, I would get an oil pressure warning for a second - now, with it prefilled prior to install, no more warning and the pressure gauge climbs up immediately. I do this on all my cars now, except the DFI Cayenne where the angle of the filter canister housing doesn't allow for that - 997.2 may be the same.

mikemessi

Agree. And for all those reasons I don't drain overnight. Just for 1 hour. My oil looks basically new when changed. The OCD in all of us results in changing more frequently than needed and I feel the cold start issue is a bigger contributer to wear than getting out that extra quart of still pretty clean oil.

Wayne Smith

I'm not seeing the difference between draining the oil overnight and letting the car sit overnight (or in between drives). Either way you have a crankcase full of oil and a drained motor.

OK ... The difference is oil in the filter. When I used to wrench for a living I'd prefill the filter during a change to avoid start up starvation (when possible). Someone much smarter than me pointed out that the fill time was insignificant. I don't do this anymore.

I agree that primary wear occurs in the first few miles of driving. That's the time to take the most care.

I also agree we are a bunch of OCDs!!! But there are enough of us that we must be right

Bruce In Philly

Isn't the computer smart enough to prime all tensioners etc? All it has to do is delay ignition by a slight turn of the crank.

Regarding residue settling out of the oil..... um.... I am not so sure about this. The oil filter takes out anything bad. The oil in our sumps is actually fairly clean of damaging chunks. The microscopic stuff still in there is in suspension. Otherwise all the black stuff would settle out and the oil would be clear again. Did anyone actually see this happen? Anyone see sludge at the bottom of a spent oil jar? It sure doesn't in the spent oil bottles I have gathering up like a military waste dump site. Besides, 8-9 quarts of oil flowing quickly out that hole does some pretty good agitation of its own.

How much went in...... About 9 quarts. Hard to say exactly because I had a 5 quart bottle with an odd small amount in it so I had to open three 5 quart bottles. Now the gauge reads one notch below full. My typical fill process is put in less than came out... or more to the point, target a low gauge reading. Then I drive it around until hot, then read and top up. Even then I don;t top up all the way.... every other fill, I can get some goofy inconsistent readings so I don't want to over do it. Usually I top up again a few days later. We are talking about small amounts... I like to get it all the way up or one notch down as it is now. I usually add when it is below half.

Peace
Bruce in Philly

docdrs

DesmoSD

I just check the current temp in Philly... 88 F/31 C.

Do a cold oil change in mid Jan at midnight and then post up the results. haha

ocgarza

Which should give a pretty full reading, even with a copper washer

Tj40

I wondered about this and then realised that you pour the oil into the top of the engine - so won't you have coated at least some of the parts? Then I realised it's a flat six!