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Optimum oil temperature

25K views 65 replies 28 participants last post by  MidEngine-Fan 
#1 ·
As everybody know sport mode lowers the coolant temperature and by doing so also lowering the oil temperature. In my case normal mode gives me about ~105C/221F and sport ~95C/203F (when more or less just cruising along). Quite a big difference and what i am trying to figure out is what is more optimal for engine lubrication. I really dont care about mpg (higher oil temp gives better mpg that i know), i care about whats best for the engine. But higher temp also means better flow (and cooling?) I use the factory fill Mobil 1 0w40, and drive a 981CS, but this apply to all water cooled/ variocam engines, any thoughts?? ?
 
#2 ·
I tend to not second guess the designers of the vehicle. It is designed to run normally in the 220F-225F range, so I'm going to go out on a limb here, and say that is what they intended it to run at. The extra cooling in sport/sport+ modes is simply to keep it from exceeding those normal operating parameters, and not to suggest it might be a better operating temp.
 
#3 ·
Im different that way, I DO second guess the designers :). Everything nowadays is about fuel efficiency. In order to conform to new strict environmental laws and to be able to sell cars, i worry that the focus that before was on performance and reliability is somewhat shifted. Its give and take, take a little reliability here, gain mpg and lower emissions there. The motor oil at 225F is quite much thinner than at 198F and in my mind im thinking less protection between moving parts. It would be fun to know what others think because i tried to read up on oil, viscosity, shear stability and so on... and now my head hurts :hilarious:
 
#4 ·
Why are you concerned about something you can do nothing about?
Porsche Engineers designed your car for many parameters.
You are not privy to those parameters.
As long as it does what you want on the street and on the track, so what?
I do know about oil use and care less about the temp, I have 18k miles and I don't know how many Track hours on my 981B,
it's a solid as the first day I drove it. If there is an oil temperature problem, I will get a message in the TFT display.-Richard
 
#6 · (Edited)
Why are you concerned about something you can do nothing about?
Not concerned, just curious :). And I can do something about it... with a flick of a switch (from normal to sport) i get an oil temp that is about 15C lower at normal cruising speed. What i wanted to know was which of these scenarios was best with the oil and engine in mind.

I cite from "Calling All Engineers" by Dr. Ali E. Haas:

QUOTE: More confusion occurs because people think in terms of the oil thinning when it gets hot. They think this thinning with heat is the problem with motor oil. It would be more correct to think that oil thickens when it cools to room temperature and THIS is the problem. In fact this IS the problem. It is said that 90 percent of engine wear occurs at startup. If we are interested in engine longevity then we should concentrate our attention at reducing engine wear at startup.

Oils are chosen by the manufacturer to give the right thickness at the normal operating temperature of the engine. I will say this average oil temperature is 212 F (100C), the boiling point of water. On the track that temperature is up to 302F (150C). It is important to realize that these are two different operating environments and require different oils. UNQUOTE


Therefore in the phase of heating up the engine I always drive in Normal mode and continue for a while at >100C so that the water in the oil may evaporate. Then I move to Sport mode, which indeed at cruising will yield an oil temp of some 95C. I don´t drive on track, but with spirited driving in Sport mode I get to around 108C. No worries.
Ernst

I found the article you referred to, really interesting reading, thank you! And my engine heat-up rutine is identical to yours :) //Christian
 
#8 ·
#34 ·
Mine pretty much lives in sport mode (Love the auto rev match for putting around town) and usually cruises around 202-210. On a hot day on track (when really pushing it), it'll get up to 240, which I, being the ignoramus I was, thought might be too high and ended my sessions early. Silly me.

But I've never cruised at 220. Didn't know it was the sport mode.
 
#14 ·
You're probably right...but in the case of M1 0w-40 its a difference from 16.8 cst to 12.2. Probably not even noticeable, and probably the same wear on the engine either way... or is it ?:). As Ernst quoted a few posts back " It is said that 90 percent of engine wear occurs at startup. If we are interested in engine longevity then we should concentrate our attention at reducing engine wear at startup. ".
 
#19 ·
From the 2013 Technik Introduction for the Boxster/Boxster S:

Operating condition: At operating temperature 185° F (85° C)
• Driving program: Sport/Sport Plus or: performance-oriented driving in the
Normal programme
• Coolant temperature approx. 185° F (85° C)
The coolant temperature is reduced to 185° F (85° C) in Sport/Sport Plus mode
and with a sporty driving style in Normal mode in order to improve the performance
values through improved charging.
Map-controlled thermostat
The temperature reduction is achieved by electrically heating and therefore opening
the map-controlled thermostat (11). The map-controlled thermostat is completely
open at an expansion element temperature of 239°

http://www.planet-9.com/downloads.php?do=file&id=402 Great reading :)
 
#27 ·
Just passed 300K on my F250 diesel :), but I agree it is a rare thing these days




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#22 ·
I hope everyone realizes that the oil temperature indication on a car is a bulk temperature.
The oil that actually provides lubrication experiences a much higher temperature.
I tried to find information on whether the sensor is before or after the cooler but no luck.
Anyone know?
I use Mobil 1 and have no worries.-Richard
 
#33 ·
There is a range of operating temperatures for which the engine performs to spec. The range of temperatures is going to vary depending on the engine and the type of oil. Just because some 1985 911 was happy between 180 and 210 on 30 year old dino oil doesn't mean that your 2015 Cayman is limited to the same temperature range. Improvements in both engine technology and oil technology are going to widen this range.

The engine oil temperature on 981s is out of the blue (cold) at 160F and does not reach the red (hot) until a very high temperature indeed. Porsche knows what is too hot for the oil and believe me, the car will tell you if the oil is overheating. Porsche has every reason to be conservative with the oil temperatures and if they tell you its ok, then it's ok. I wouldn't think too much past that.


All of that said, I regularly see 230F for the oil by cruising around in normal mode. I can absolutely guarantee you that Porsche wouldn't let the oil overheat by simply cruising down the highway at 75mph in "normal" mode, so I have zero worries about a 230F oil temperature. I've seen as high as 253F on the track in Sport Plus and guess what? It's still not in the red and I'm still not worried about it. Engine oil analysis on my oil after 4500 miles of hard driving reveal a perfectly healthy engine.
 
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#43 ·
Yup. Sport+, 95 degrees at Lime Rock. It was my first DE in the Spyder and for some reason, I felt the need to really push it. I knew I gave the car a little bit of a beating that day. Stupid of me but the blood was flowingZ

Okay, so 240 is a bit high in Sport+? How effective are cool down laps on a hot day like that? Or is pitting the smart decision? Anything else that could be done in the future (ice or something)?

Truth be told, the car outlasted me.
 
#36 ·
I've had mine to 253F during a 20 minute session at 95F ambient temperatures. I still don't think its a problem. Mobil 1 is rated to 500F according to the manufacturer.
 
#37 ·
I'm pretty amazed at the difference for street driving the Sport button does for oil temps - I can be cruising along, not pushing too hard in Normal and get temps of 110 C. Going to Sport mode will drop that temp all the way down to 85 C in about 5 km of driving.
 
#38 ·
some more data: my 2016 car (2.7L pdk) is on the break-in period with only 1,350 Kms (city =55%, highway = 45%) to date and the highest I have seen is 109*C (228*F) oil temp. on highway fast drive. Is this too hot?
 
#44 ·
14BS here. I've seen 255 at the track when I was really thrashing it (lots of second gear at 6,500+ RPM. When I noticed it was that high, I kept driving but used less 2nd and after less than a lap it dropped to about 230. When the temp gets too high for your comfort level, you really ought to keep driving it, but at a lower pace, so it will cool off. If it's too hot and you park it, you're sort of baking the whole engine.

Another thought: Mobil 1 advertises it's good to 500 so 240 for a short period really shouldn't hurt anything.
 
#46 ·
Seems like, if the car gets short trips in between long ones, you would want to get the oil up to 100C, in order to thoroughly boil away any water.


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#49 · (Edited)
FYI, my water temp in my 981 CS And my 991 C2S sit right at 194F all the time after 5-10 minutes of driving. That is the thermostat calibrated temp. But my oil temp in my 981 CS reached 235F on the Interstate at 75-80 after 20-30 minutes in 80-85 F weather, and on the track after a 30 minute session in my 991 C2S, 230F in 85-90 F weather. Those are quite acceptable temps in these modern engines with 0W-40 synthetic oils.
 
#50 ·
I don't think oil temperatures in the typical ranges we are seeing (< 250 degrees ) are an issue at all. Mobil states on their website the the oil has been designed to withstand 500 degrees.

I think that the manufacturers have dumbed down the water temperature gauges to reduce the angst of their customers.
 
#61 ·
With just a buffered coolant temp gauge, you never know how hot your oil is, especially without an oil cooler/heater, which is the case for most cars on the road. And some sports cars with oil coolers are the air-to-oil variety, especially on older cars. My 2012 Corvette was a case, and oil temp only got to 120s in winter, but GM finally changed to coolant-to-oil coolers in 2013, I believe. Oil heats up much slower than coolant (also cools slower), so you never know when it's 150+ to safely go to WOT/redline. But with an oil temperature gauge and coolant-to-oil cooler that also acts as a heater, it gets there much quicker. And you always know when it's safe to push the engine. We don't really need an accurate coolant temperature. And the good news is if coolant gets hotter than 221ºF, it'd show on the gauge, so not a big deal at all. Not having an oil temperature gauge on a sports car would be a huge deal for me. What I'm disappointed about is not not having an accurate coolant temperature gauge, but not having a transmission temperature gauge at all, especially with PDK. It has one, so why not making a gauge available? And one for the manual tranny would be great as well. Oh well.
 
#63 ·
Synthetic oils are remarkably resistant to heat damage. I would not worry about running 220 versus 235 if you are using a synthetic motor oil as mandated by Porsche. I never use sport mode because I can't stand the farting with PSE so run it in normal and my oil temperature is always between 225-235oF.
 
#64 ·
Do you have the ventilated seats? -- sorry, couldn't resist


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