[mitosis]

Originally Posted by ZionsWrath

If you let it idle for 15 minutes in winter and get in thinking it is warmed up and drive it more than gently, guess what you transmission, differential, and all suspension components including tires and brakes are still ice cold.

This is a very good point, and is the fundamental reason why someone like me would be of the opinion that with a modern car is it actually a BAD thing to let the car warm up by just sitting in the driveway idling. You're much better off actually driving the car, gently, until it is fully warmed up instead.

Originally Posted by Porsche

Will you tell us, please, how many MINUTES of gentle driving do you find it generally takes for the oil temperature to rise to 185° F.

Well, it's looking like about 8 minutes in every one of those logs before it FIRST hits that temp, but I'd say it wouldn't be a bad idea to still wait for at least 10 minutes before driving the car too hard.

Originally Posted by ZionsWrath

Can you post a graph of you starting the car and driving off from a dead cold start? How long to reach operating temp?

OK, now on to logs!

Some general notes for these logs:
-Startup is at about 6:40 AM on each of these.
-Not every chart starts exactly at engine start, sometimes it takes a bit for the bluetooth to connect.
-The vertical lines represent 1 minute each.
-I am logging to the file every 5 seconds, so the numbers on the bottom represent how many data points are there... point 1 is the first data point, point 13 is one minute later, etc.
-Ambient air temp readings start off a little high but stabilize soon after the sensor starts getting some airflow over it.
-Intake air temp will match the ambient temp at first but once the engine is warm and the car comes to a stop you can see that heat soak creeping in.
-Engine load spikes that show up just before vehicle speed decreasing are throttle blips and rev-matching on the downshift, load spikes that show up just before vehicle speed going from 0 to something are launches.
-The engine load measurement on Torque seems to be WAYYYY off sometimes... for example this morning I was trying really REALLY hard to baby the car so we could get the slowest possible heat-up for the sake of getting a worst-case number for Porsche, but for some reason Torque STILL shows 75% to 80% loads even when I was barely creeping along on surface streets.

August 26th:
Ambient air temp was 64 F.
Looks like I drove it very gently on the freeway that day.
You can really see the neat correlation pattern between heat soak and vehicle speed in this one... look at those lumps on the intake temp near the end and how they all line up with the low points on the vehicle speed (stoplights).


August 28th:
Ambient air temp was 64 F.
Looks like I drove it more normally on the freeway this day.


August 29th:
Ambient air temp was 66 F.
More of the same.


August 30th:
Ambient air temp was 64 F.
Looks like I got stuck behind some slowpoke about halfway through my freeway trip on this one... you can see my impatience in the way the engine load is all spiky like that around the 6th and 7th minutes, lots of on and off the throttle wishing I could go faster there.
Got quite a few hard launches at 100% engine load starting at about 10 minutes, must have been making up for being stuck behind the slowpoke.


September 17th:
Ambient air temp was 62 F.
The gal in front of me on the freeway onramp was a dinosaur, you can see where I got fed up with her slowness and gunned it to pass about half way into the 6th minute.


October 4th:
Ambient air temp was 62 F.
I had trouble getting the bluetooth to connect this morning so there was an extra minute or two of idling before the chart starts.
I was putting out extra effort to drive very gently this morning, especially for the first surface streets from the driveway to the freeway.
The car had not been driven all day yesterday and it was a cold, windy day yesterday so this morning it should have been one of my coldest starts yet... the minute or two of extra idling while sorting out the bluetooth kinda ruined that though.
I still think that this chart represents a good worst-case scenario (that is for now, since the weather is still pretty warm at 62 F) for answering Porsche's question of how long for oil to warm... just add a minute or two on to the 7 minute time that this chart shows.