I was wondering,
now that it's freezing here (ie., 10-15 degrees Celsius below zero).
Does the ECON button have a purpose?

 

speaking of cold weather, i recently drove up to the snow for a snowboarding trip and the water temperature would not stay at exactly half way like usual, it went down a little. do you guys in the colder states get that too?

 

the water temperature? --> engine temperature?

If it's that, then no it isn't normal. Mine would decrease driving higher speeds cuz my thermostat was stuck Open.
You can change it quite easily on a 1.8t aeb from underneath. Part cost 20$.

I don't mind this thread being high jacked, but please answer my question also! XD

 

i have a 2.8 engine and also have the part but never changed it cuz my thermostat works just fine. it was just when we reached the very cold temps that my temp decreased a little. if my thermostat was stuck open, wouldnt the water temp be down at all times? :P i noticed that the temperature was at like half, and when the thermostat opened it would drop a little but then it would go back up. once i got out of the cold it was stuck right in the middle

 

Well, I had the thermostat stuck for almost a year (ie., summer/winter).
In winter, then engine would heat up to about 1/4-1/3 mark, and would lower slightly on highways.
In summer, it would heat up to 1/2 mark, but would decrease as my speed increased on the highway.loll

maybe someone else will post another cause, but Plz! Reply to my initial question too!

 

A decreasing temp gauge is also and is often the symptom of a bad Coolant Temp Sensor, a common failure on our cars. If a thermostat sticks in the dead of winter you would likely never get heat if im not mistaken.

To answer the econ mode question, it does not have a purpose, when the outside temperature gets cold enough (37 degrees F i believe) the A/C compressor is prevented from coming on. This is the only purpose of the econ mode button anyway.