It's not for my a4 but my girlfriends 01 jetta. Did waterpump t stat and timing belt Saturday and currently using water. I know your shouldn't mix coolant but if I flush it out can I use regular coolant? What is g12 specificaly and what makes it different then regular orange or green coolant? Is this just vw way of keeping your pockets empty or is there another route I can take? I know water won't damage the system and it's not going to freeze this time of year but I just think it's rediculous to have to put a expensive coolant in a car. Engines are engines and are all cooled in a similer fashion, am I right? So my question is, once flushed is there at harm to using standerd coolant?

 

Yes, you can use whatever coolant as long as you flush it out. Note that draining it from the radiator is not flushing it. It really needs to be flushed out. Do that and you can use traditional, G12, even GM Dex Cool if you want. Just don't mix.

 

Ok sweet, also I'm a little low on my g12 (just at the min mark) is it safe to add a little water or should I go to the dealer and get a top off bottle?

 

water is fine

 

Used distilled water, NOT tap water.

 

^ I used tap water almost 10k miles ago and I have no issues. But then again I have a well and use soft water, not hard.

 

You "probably" won't have any problems, but distilled is still better. Tap water has contaminants and minerals dissolved in it that can cause rust, corrosion and deposits. Coolant helps reduce these ill-effects but it can't completely prevent them. Soft water is has less calcium in it, but more sodium in it (among other things).

Distilled water is cheap (99 cents a gallon), and it's what is best for any cooling system.

 

I've had tap water and green coolant in my car since I bought it hahaha. 26000 miles ago

 

You might want to consider changing it. Whoever put that tap water in your car didn't know what they were doing.

 

I've always put tap water in all my vehicles and they run fine. My buddy uses tap water in his Focus all the time and it runs like a top.