This question has been lingering in my mind for a while. Coming from the Audi turbocharged scene I have grown to use, depend on and appreciate the oil temperature gauge found in many Audis. Indeed, in a turbocharged car I can see the need for knowing the temperature of the oil: that in turn would tell me how far I can rev the engine and request boost – OK, it isn’t a scientific equation, but still…: some of you may be surprised to know that on a cold winter morning after garaging the car all night it still takes no less than 15 miles of gentle highway driving to get the oil near optimal temperature. 15 miles!

In the 911 Turbo, however, the cluster includes an oil pressure gauge, but no information is provided about the oil temperature (unless I missed it). I do understand that in case of imminent engine failure knowing about oil pressure would be certainly more beneficial than knowing its temperature, but wouldn’t the oil pressure light below the gauges be nearly equivalent?

What am I missing about the relevance of the oil pressure gauge?

 

What about the temperature gage? I mean that should be a very good proxy measurement of the oil temperature, right?

 

The 996TT motor is a derivative of the air cooled motor used in the prior 993TT. (These cars as with all prior Porsche have an oil level, oil temp and oil pressure gauge as these were the most critical measures of engine heat conditions). The 996TT is not fully water cooled (unlike a 996na) but has water cooled heads similar to the GT cars. Hence the engine is both water and oil cooled. As the water cooled heads are only doing part of the work, and absorbing heat from the oil, the temp gauge is a combination of both oil and water temps. You can always install a separate oil temp gauge using a sender plugged into the oil coolers if you are uncomfortable with the stock temp gauge.

All engines should be driven about 15 minutes in normal street conditions before engaging in aggressive driving. It takes this long (regardless of temp gauge readings or type of cooling systems) for all the engine componets to reach optimum performance temperatures.

 

I'd be willing to loose all my gauges but the oil pressure as I consider it to be the most vital one.

 

It's not only an indicator but a diagnostic tool.

After driving the car for some time and having the "normal" gauge readings in your mind when one is out of place it is easy to see that something may be amiss. I used to do the warm up "time thing" till I got used to the gauges. Cold, my car reads <180 on the temp and 5 bar on the oil pressure. As the temperature of the coolant and oil get to running temperature the temp gauge reads 180 and the oill pressure is still 5 bar. As the engine reaches operating temp the oil pressure drops to 3.5 to 4 bar. Now I know the car is at operating temp without having to pay attention to time or miles. High oil pressure, low oil pressure, pulsing oil pressure. Any of these suddenly come on you know something is wrong.

 

mind blown

 

One of the things I've been doing is using the oil level function on the car as a way to test the oil's temperature. It's not direct, but the car won't sample the oil level until it's "hot" which I'm guessing is at least high enough to provide adequate flow under aggressive conditions (>160f?)

Speaking of, does anyone know the temp at which the oil level test will start working?

 

Same here

 

And it would have been great with an added fuel pressure one as well

 

Really? It informs you directly of condition of motors lubrication system AND gives you time to catch it before it causes catastrophic damage..

 

i'm with folks on the oil pressure gauge if i had to pick one. i know nothing but enough to know if that gauge drops suddenly i will immediately implement the lemans start in reverse

 

There is a oil temp sensor that the ecu reads. It is right behind the oil filter housing. You can see the sender part when you change the oil filter.