Conventional wisdom says it takes twice as long for the engine oil to reach operating temperature as the engine (coolant) temp. That has always been generally true....until now. I have been monitoring this in the Boxster and it's way different from any other car I've owned.
First off, for monitoring I used the Durametric OBDII reader for Porsches. It's wonderful and it allows me to read all of the codes for the alarm system, airbag, A/C-heat system along with the regular OBDII codes. It also allows me to see real-time stats.
So here's what I observed. The normal operating temp for the engine is at 195F. The normal operating temp for the oil is 200-205F. As the engine temp rose, the oil lagged behind a little. Once the engine got above 180F, the oil temp started rising faster. As soon as the engine reached normal operating temp, the oil was 200-202F. I have watched these readings several different times from first morning (stone cold) start to a lunch time start when it sat for a couple of hours and it's always the same. I'm guessing the oil squirters allow the oil to flow much better and it warms up faster with the engine.
So bottom line seems to be the engine temp and oil temp reach their normal operating temp at pretty much the same time. :dance:
For a side note...the white line to the right of the 180F mark is 235F. I always thought it was halfway between the 180 and 250 (overheat) mark so that was a surprise when I ran it hard and got the temp up to that line. Just a little FYI.