No, but I've read here that it accesses an extra oil cooler. If so, I've wondered if it could be over-ridden to remain open?
Also, has anyone figured out how to make the coolant temp. read actual temp, not the program-limited 194?

 

I have seen my coolant temp way over 194. Odd that you are not seeing higher temps.

 

Porsches use a complicated cooling system, unfortunately. It's not the typical mechanical thermostat; it's an electronically controlled contraption, which is more prone to failure as miles accumulate. In normal mode, coolant is a ridiculous 220+, so I always use sport mode too, which brings temp down to normal levels. And yes, Porsche also buffers the coolant temperature gauge, like almost all other automakers (only Corvettes show actual temp, as far as I know). That means temp is always parked at a set level while at normal range (185-235 or so), until it climbs above it. But the good news is Porsche shows actual oil temperature, which to me is more important. And since the oil cooler is a coolant-to-oil one (rather than air-to-oil), it should closely follow coolant temperature. Hope this helps.

 

Actually the system in the 991 is straightforward. When you press the Sport button, among other things you also activate a changeover valve that opens the passage of engine oil to the water- to- oil intercooler (like a radiator) mounted above the engine. The oil temp drops by around 20 degrees F. (typically from the usual temp 210-220 to about 190).

 

I don't think this is correct because that oil/water heat exchanger is the only method for cooling the oil on these cars and it's always in operation. It also helps warm the oil during a cold start. If you use an app like Torque to read your actual water and oil temperatures during mild driving when the engine is fully warmed., you'll find that the oil and water temp are both right around 220, which is exactly what you'd expect with an oil/water heat exchanger.

I think the correct answer, as stated above, is that the engine uses an electronically regulated thermostat and when you select sport mode, the system simply drops the temp to more like 175-180, if you're not driving too hard.

However, in a 20-minute track session on a 100-degree day last summer, the water temp still got up to 226, while the oil temp reached 246. (by the way, intake air temp hit 170). Under those conditions, the optional third, center radiator would be worth the cost and weight.

 

I have NEVER seen my water temperature gauge above 194. In sport mode the oil temperature hovers around 194 as well. With harder driving I can get the oil gauge to climb to 235, but that's as high as I have seen it. I think someone wrote that the emissions system works better in normal mode (non-sport/non-sport +) and reduces the carbon footprint at higher temperatures. Since heat is the enemy of everything mechanical, and my car is more fun in sport mode, I drive it in sport mode 99% of the time.

 

I agree that heat is the enemy to everything- but I wonder if that might also be to the detriment of the longevity of our engines in other ways.. for example, I would expect a hotter engine to better cope with carbon deposits than an engine that only runs on the cooler end. My habit is to drive the car in normal mode (oil temp about 220+- for the majority of the session, but switch to Sport mode within a few miles from my destination to allow things to cool down so that I'm leaving the engine a bit cooler by shutdown.

 

That's because the water temperature gauge lies--or is buffered, as some might say. If you use any means to access the water temperature sensor used by the engine management system, you'll find that your car is running at 220 degrees, when the gauge reads 194.

Haven't you noticed how the gauge NEVER departs from 194 once the car is warm, no matter what you do and how you drive it?

 

Well not everything...I'd rather live here in FL than NY where I was born.

And no, it is better to run a cooler engine.

 

 

Unless you live in an extremely hot climate or drive hard enough to exceed the limits of the standard cooling system, it will likely have no effect other than to make your wallet lighter and your car heavier.

 

 

I always run in sport plus but sometimes I will turn the suspension or exhaust setting off. Running 20% cooler means everything is going to last that much longer. Running cooler also means the engine is more efficient (think Cray Mainframe waterfall). Also in 15 years I don't wanna replace all the seals and gaskets so perhaps I can make them last a little longer (even though rubber normally is designed to fail in 10 years).

 

No, I don't think there is any secondary cooler. When you select Sport, the engine management system simply changes the target temperature for the water cooling system from 220 to about 180. It does so by regulating the adjustable thermostat.