G11 vs G12

[QSHIPQ at aol.com]

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TSB199601 from VW/audi says to change all G11 (blue) to G12 (pink) coolant
(corporate wide switch 96/97MY vw audi).  The G12 is "supposed" to have better
conditioning properties, stability, etc....  The procedure for old to new swap
is to flush with distilled water with heater on, making sure that you have
flushed the engine as well as the radiator (read: thermostat must open during
procedure).  Then purge with compressed air.

I'll put forth my .o2 on this subject.  IMO, you should stick with whichever
coolant you got from the factory.  If your audi is pre 96, then use the Blue
G11, if it it post 96 use the Red G12.  Mix them exactly as stated in the
owners manual/Bentley/expansion tank label.  Use ONLY distilled water in the mix of
either coolant you choose.  The advantage to G12 is a longer silicate
stability (read: long life).  If you routinely flush and fill (every 2 years) with
the proper procedures above, you shouldn't find any problems with using G11, and
the debate on which is "better" really is moot.

I personally refuse to do "the swap" in my shop.  Whatever is in the motor
when it comes in to my shop, is what I use when it leaves.  I'm not at all
convinced that even with the best of drain and fill procedures, that you've
addressed purging of all the "old".  YMMV.  One issue that I've read (no btdt) is
that the swap of G11 to G12 on the old fibre head gaskets can lead to premature
failure of head gaskets.  This doesn't apply to the S car, since it is all
steel anyhow, but could affect all other cars of the pre 96 audi line.  The
argument presented is the "warning" regarding mixing the 2 coolants, basically
manifiests itself in a G11 soaked head gasket that is now immersed in incompatable
G12.

My own belief is that the G12 is more "tolerant" of bad mixes, non use of
distilled water and possibly a better long life stability.

Following the proper procedure in either coolant application is the key to a
good coolant in your audi.  Water wetter (all anecdotes and testimonials
aside) is a no-no, in fact ANY additive is a no-no.  The baseline for A/F is the
alkaline content of the mixture, which you alter with the use of additives.

The debate appears to be a rage, even within manufacturers of audis/coolant.
IMO, with proper procedures, either coolant designated for your automobile
should prove most adequate to the task at hand.  If your car has been "swapped"
best leave it that way, no sense in "another" swap, whatever issues are
already expost facto.

HTH and my .02

Scott Justusson
QSHIPQ Performance Tuning
G11 fleet
'91 v8
'87 T44tqw
'84 RS2URQ
'83 Urq



In a message dated 6/2/2003 9:05:51 PM Central Daylight Time,
chadaclark4 at msn.com writes:

Folks,
>
>Just returned from CT.  I wound up missing the Greenwich Concours
>entirely due to wedding attendance and rain rain rain.  Man O man =O
>
>Anyway my sisters urS'92 in a word is great.  IMHO '92 was perhaps the
>best year, abs on/off, more aggressive software, funky interior wood,
>forged wheels, dual pissers and most importantly, a great suspension.
>Very nice.
>
>Does it really matter red vs green Audi coolant?  They put red in her
>car but my car takes the green.
>
>Would any CT (southern CT ) lister know of a good place to get the car
>painted??  How much should a 'good' job cost do ya think?  She has balck
>with grey interior and new paint would make the car new IME.   A three
>spoke wheel  would be nice too.
>
>Thanks in advance!
>
>Cheers'
>
>Bill m