Auntie Freeze

[Mike Arman]

I remember a discussion about different colored anti-freezes recently, and
why are they all different colors and which one should I use in my 5000,
100,200, A4, TT, etc.?

This came off another list, and I though it might be interesting.




>Propylene Glycol (the purple-pink stuff) is a 'safe' (less toxic)
>antifreeze.  It is used in RV water systems during winter storage
>since a little bit left over after the Spring flushing won't harm
>you. It's available in WalMart and Home Depot (hot-water baseboard
>heaters use it as well).  Automotive stores carry the stuff as
>Prestone "LowTox"
>
>Ethylene Glycol (the yellow-green stuff) is poisonous, though less
>expensive.  It is the common antifreeze used in car radiators.
>Ethylene Glycol also comes in orange in some newer cars.  The
>difference is in the additives - yellow-green uses silicates for
>corrosion protection, whereas orange uses organic acids.  Orange
>lasts longer in a radiator but only if all the components are
>aluminum and steel (no copper or brass).


Audi is using "the pink stuff" lately, probably because it is less
environmentally nasty.

For some reason, dogs and cats like to drink from pans containing the green
stuff. It will kill them, so keep your pets away when you are working on
your car.

The orange stuff only works if you don't have a copper or brass radiator.
(If you later install one of the all-metal radiators, you'll need to change
from the orange anti-freeze to another color.)

So:

Purple-pink, less toxic, more expensive (Propylene Glycol)

Yellow-green, poisonous, cheaper, silicate additives for corrosion
prtoection. (Ethylene Glycol)

Orange, long life, organic acid additives for corrosion protection, hence
no copper or brass cooling system parts allowed. (Ethylene Glycol)

I also understand that some of these don't mix well together, and a
thorough flush may be needed to make a change.

Best Regards,

Mike Arman