Cyberbug

Great day for driving around 70F average,
coolant temp was rock steady at 194F through the 2.5hrs

in normal driving mode oil temp was 230F

in sport mode it always dropped to around198-201F

I suspect cooling fans are constantly on in Sport and Sport plus modes

911-TOUR

Sport/Sport+ have the cooling fins open in the front air dam. Normal keeps them closed. That accounts for the difference.

cheers!

Valvefloat991

In normal mode, the radiator vanes operate automatically, opening and closing as needed. In sport mode, the fans do run continuously. In fact, the S and GTS have more powerful fan motors than the base Carrera to better cope with the greater heat rejection of the more powerful motors.

The bigger difference is that the coolant temperature is greatly reduced in sport mode. Despite the constant 194 degree reading on the temp gauge, the coolant is actually around 220 degrees in normal mode and the thermostat lowers it to about 180 degrees in sport mode. Since the oil temperature is regulated by the coolant, that accounts for the drop in oil temp. And you see it because the oil temp gauge is not dumbed down like the coolant temp gauge.

VektorPerformance

^ Very true. Noticed the same observation in regards to coolant temps; ECU feedback is different than what the gauge displays.

spdracerut

I wonder if there's a way to hack the dash gauge so that it displays actual coolant temp. I wonder what the difference is in fuel economy in normal mode vs. sport. Porsche is definitely running the engine on the warm side in normal mode to eek out more mpg.

Lucky991

Is there any harm in the long run to always running the car in Sport mode? Thats my preference when not in heavy traffic or facing inclement weather. Will this wear the fans out faster? Hopefully not expensive to replace?

Valvefloat991

I suspect that the coolant temperature gauge hijinks are programmed into the engine management system. Perhaps Cobb could solve the problem.

As to running in sport mode all the time, it probably hurts your fuel economy a bit due both to the lower engine operating temperature and the need to supply the electricity to operate the cooling fans. I have no idea about the durability of those fans, but you assume that replacing them would be cheap, you probably haven't owned your Porsche very long.

Lucky991

I meant cheap relative to say an engine rebuild. Everything can’t cost $20k on this car. I own two 11+ year old BMW’s. Replacing a xenon light when a ballast goes out is a $1500 USD job, can cut that in half at a good indy. Water pump same thing. Sure Porsche’s are expensive to maintain but there are ways to minimize the running costs of any car with sensible and thought out approaches to any problem (source parts as cheaply as possible, find great experienced and passionate mechanics with reasonable labour rates). Haven’t seen any worrisome major issues on the 991 other than bore scoring and even that I’m not sure is that widespread of a problem.

Valvefloat991

They will certainly be less than an engine rebuild. As a 991.2 owner, I hope you're right about the basic reliability of the car. so far all indications are good. My previous car was a 2007 335i manual with sport package and I also learned the benefits of indy shops, as well as the even greater savings of doing things myself.