I usually wait till my coolant is at 200F, sitting in the middle. anyone use the oil temp gauge instead?

 

I use my oil temp...I wait until it's about half way to fully warmed up before I'll really push the car. Probably too conservative, but better safe than sorry.

 

I use my oil temp as well. I wait till it gets to about 200F which takes about 10 min

 

if the coolant is at 200F then i assume the engine is too. the oil takes waaay too long to heat up, 10 mins is about right.

what's the point of waiting for oil to heat up to 200 as well if the engine is already at 200

 

When an engineer refers to a engine's "normal operating temperature," he is not referring to a temperature based on the water thermostat. The oil temp must be up to operating temperatures as well before you get on it....oil temp heating always lags significantly behind the water temp.

So the question is...do you want to go WOT and full boost when your car is not at normal operating temperature?

The biggest killer of any motor is cold oil. Your oils minimum temperature should be operating temperature before you push it. Even if water temperature is 180 degrees, your engine oil can still be at ambient temperature.

Let your car idle for approximately 5 minutes...the head water temperature will reach approximately 180, but your oil temperature will still be at ambient temps.

 

so i'm thinking about how temperature makes a difference for performance of engine oil. the purpose of engine oil is primarily to lubricate the moving parts within an engine. if that being the primary function (with a few other things as well), how does temperature affect engine oil?

i think we all know that as temperature rises, engine oil becomes less viscous. I'm sure that there's some optimal viscosity the engine oil is at to properly lubricate the engine. that being said, there must also be an optimal temperature.

so i did some quick research, and it looks like the relationship between temperature and motor oil is logarithmic. Once you hit 50C (122F), the change in viscosity is almost nothing all the way up to 200C (212F). Check out this link: http://www.widman.biz/English/Calculators/Graph.html

As a note... I took my car out for a drive earlier and saw that right around when my coolant hits 200F my oil temperature is around 120F. Granted I assume the oil temp will take longer to heat up if sitting at idle, but if driving normally by the time your coolant hits halfway i think your engine oil is ready to go.

 

So when I take my CTT out in January, when it routinely hits -10F, and let the coolant temperature reach halfway, I am good to go?

 

halfway between the temperature gauge, if i'm remembering correctly my coolant temp gauge is between 150F and 250F, so 200F being the halfway mark

 

Thanks for the explanation and info

 

I do not know the specifics for the Cayenne, but there are several excellent discussions in the 996TT section about warm up, engine temperature, and when it is "safe" to go WOT.

Applying the same principles, you should be able to start the car and go. But to address the OP's remarks about "driving hard"...the coolant temperature and engine operating temperature are not the same - and going WOT when your coolant temp is "half way" is a good way to decrease the longevity of an engine.

 

Great explanation bbywu! That is exactly why I dont "punch it" or go WOT until the oil temp is around 200F for a good amount of time

 

I don't wait, I get in and beat the hell out of it.

 

I have to agree here in that the coolant temp and the oil temp do not necessarily correlate. On my M3 I actually have 3 diff. indicators, the coolant temp, the oil temp, and the RPM gauge. The RPM gauge indicates the max recommended RPM's you can go up to before the car is warmed up so that you can go WOT (there are lights). It starts off 4K RPM's on a cold start and slowly inches up to 8K RPM's when fully ready/warmed up to go WOT. The timing of movement of the RPM gauge and oil temp gauge are fairly correlated while the RPM gauge and coolant gauge do not directly correlate.

 

Remind me not to purchase a car from you.

 

You just took the words out of my mouth, Bob!