pete13

So I was ruminating today whilst on a drive, and I'd certainly like to hear the thoughts of those more erudite than myself on the topic. I was wondering what the correspondence between the water temp displayed on the dash and the actual temperature of the circulating oil in the engine is. The question was prompted initially out of concern for wearing a cold engine: I think of the optimal warm operating temp as being in the 180-190ish range on the dash display, but when starting from cold, does the fact that the water temp (according to the dash display) has gotten up to 180 indicate that the oil is sufficiently warm to safely allow spinning to redline? Or, does the fact that the circulating coolant is at optimal temp not reflect the temp of the oil, and as such is a further warm-up period required?

My inclination (betraying my ignorance maybe) is to think that the oil would warm up more quickly than the coolant, because it's directly exposed to the heat-causing surfaces, and would thus heat up more quickly than the coolant that has to wait for the radiant heat to pass through the aluminum cylinder walls. However, I feel like oil would be more temperature retentive (higher specific heat capacity, IIRC), plus there's more of it, so I hesitate to make that my final answer, Regis.

So, those of you who know more than me, or even if you don't, let me know what you think the right answer is, and maybe we can figure out what the right answer is.

pete13

Also, let's hear what your warmup habits are, I usually idle in the garage until the secondary air assist turns off, then (try to) keep it under 4500rpm until the dash is reading 180.

jsmirand

What's the purpose of the add'l marker on the temp gauge towards the left side of the temp dial?

RallyJon

No. Never, not in any car. Oil temp always lags coolant when warming up.

In every car I've owned, I wait until the oil temp is 160-170 before getting on it. 996 is the first car I've owned without an oil temp gauge. Yet, more knowledgeable people than I recently posted how the 996 is tough on oil.

No, I don't understand, either.

RGrnwd

I consider oil warm enough once oil pressure reads 1.5 - 2.0 bars at idle. When cold, it reads 4.5 - 5.0 bars at idle. Until up to operating temp, I keep revs down...3k rpm on freeway, shift between 3k & 4k max.

VGM911

Two thoughts come to mind....one is, why do you run an idling car in the garage????

Secondly, conventional wisdom is that nearly every car can/should be driven without an idling period (and prudence dictates that you don't floor it until you've driven a few miles to warm it up, especially in cold weather).

If your question is more about redlining it, one should wait until fluids and tires approach or arrive at operating temperatures, especially Z-rated tires in cool/cold weather. I'd guess that even transmission/transaxle fluid protects better when it's warm.

Edgy01

Don't think too hard about this one. Drive it easily for 5 minutes (check your watch) before you punch it. Keep in mind that the water temp gauge lies to you,--it's been intentionally dumbed down by PAG.

The light weight oil we run in these cars gets up to temp. fairly quickly. If you're in Fairbanks, Alaska, you will naturally give an engine time to warm up before you push it,--do the same with where you are, tailored to your environment. If it's the winter time, you just take a little longer.