coolant for an 02 Legacy?

[Edward Hayes]

Valvoline product. Zerex antifreeze G05

 

[y_p_w]

Valvoline product. Zerex antifreeze G05

Valvoline (Ashland Oil) bought the Zerex brand name from the
German chemical company BASF. The G-05 formula was
developed by BASF, and they still seem to be making coolants
in Europe for the likes of BMW and VW.

I don't know if Subaru OEM is silicated. I would suspect that it
does have the typical Japanese manufacturer's use of phosphate
inhibitors. If it's a low-silicate, phosphate, plus some organic
acid, then maybe regular Peak or Zerex would be a closer choice.
I don't know why there are so many who rail against organic acid
inhibitors. The evidence seems to be that they've been used for
years along with other corrosion inhibitors. The main thing about
Dex-Cool is that it ONLY uses OAT inhibitors.

I'm not sure exactly what's in the Subaru requirements. I see small
amounts of coolant residue on my overflow bottle tube and assorted
places where it's spilled. It could be silicate and/or phosphate
residue. I'm thinking of sending in a small sample to Blackstone
Labs just to satisfy my curiosity. Of course I used it up, but I
could
always get another bottle for my next change.