Mixing Coolants
 

Everyone always says to use only the blue OEM Subaru coolant, but noone ever explained why. Well in the auto tech class I'm taking, I was informed that the blue coolant will turn into a jelloy type substance when mixed with other coolants. I can confirm that this is true because when I went to look at my car, which I topped off with some random other fluid, there was a bunch of jelly type thing at the spout of the radiator cap. Just explaining why everyone is so worried about the coolant thing! If you did mix coolants, I think its best to go and do a flush and refill.

And after flushing you can fill up with different coolant right?

If you mix coolant it will turn in to a nasty mud/jelly substance and clog the cooling system. Bad news. Don't do it.

The manual states that the factory fill is good for 11 years or 130k miles or something. if you use other coolant, it shortens the life to like 75k miles or something. That's their reason to not mix coolant. But good to know about the the jelly thing.

Well the only reason someone would mix coolant is to top it off. It seems that I wasn't the only one that had to top off the fluid.

You didn't listen until you saw jelly?

Topping off with distilled water was the preferred route I always thought.

Cheap too.

I was about to top off with another fluid until I read in my manual that mixing coolant decreases its life. spent 25 dollars on a bottle of 50/50 premix subaru coolant for the next topping off of 11 years lol

I have heard distilled water, something wetter and a cup of coolant keeps the engine cooler..

Technically a 50/50 mix is best at keeping the engine cool and I think it was like 70/30 for places with actual winters. Straight antifreeze is not good for the car, I have heard of topping off coolant with distilled water is good because the evaporation is usually the water in the coolant. I've never tested out the theory if the evaporation is coolant (antifreeze and water) or just water, but I guess you would find out by testing the concentration if you extracted all of it

What about swapping the water for something like "Evans Coolant"? http://www.evanscooling.com/
They claim the engine will run allot cooler. Anyone ever use this?

As far as i know the thermostat controls the cooling.
If the temp gets too low the thermostat closes, preventing coolant from circulating around the engine.
When it gets hot enough the thermostat opens and it starts circulating again.

So, i ddoubt changing to a different type of coolant will change anything

Edit: I see you suggested changing from water to a coolant. my bad...

Different coolant makes a difference; how big, I am not 100% sure. Running straight water your car will run cooler than straight coolant or even 50/50. In on of my old 05 STi, I was on track and the coolant started boiling when i came off. I checked everything out, flushed coolant and the problem went away the next track day. I figure the coolant was still the original fill, I filled it 60% water 40% coolant.

Your Thermostat does control the lowest temp that your car will run(after it warms up), that is why people will install lower temp thermostats. However, the thermostat temp is often 30-40 degree lower than the operating temp. Running a different fluid could make the car run at 200 vs 210 degrees.

Interesting, together with Mishimoto Race Thermostat it should have a good result.