be careful here:

if ethylene and propylene glycols are mixed, then it isn't straight
forward determining the level of freeze/boilover protection, at least with
an ordinary hydrometer.

2. green color is simply a dye, and is not a reliable indicator of coolant
type.

3. propylene glycol may be less toxic than ethylene glycol, but in both
cases the chemicals dissolved in used anti-freeze substantially increase
toxicity.

On Tue, 3 Jan 2006 08:26:33 -0800, gary hradek <hradek@YAHOO.COM> wrote:

>Robert,
>      There is very little difference between Ethylene
>Glycol and Propylene Glycol  One is a three carbon
>alcohol and the other is a two carbon alcohol.   They
>do nothing more than keep the coolant from freezing or
>boiling.   The two carbon alcohol is less toxic.
>    The real difference in coolants has to do with
>what they add to make them anticorrosive.   You should
>not  mix the different types of anticorrives but you
>could mix the different forms of alcohol.   The green
>stuff usually contain the phosphate based
>anticorrosive while the orange stuff contains the
>organic detergent based anticorrosives.   Even a small
>amount of the green stuff can cause the orange stuff
>to sludge so if you change from the green to the
>orange it is important to rinse the coolant out until
>there is no smell of coolant.   Hope this helps.
>   gary
>
>--- Robert Keezer <warmerwagen@yahoo.com> wrote:
>
>> Hi,
>>
>>  I would like to comment that I have been using
>> the orange Havoline or Prestone for about 5 years
>> in my inline four. I know it's more of a concern
>> for the WBX, so I have been using it in the
>> Vanagons I sell.
>>
>> 2 years goes by fast and it's easy for most
>> people to overlook coolant changes like brake
>> fluid or power sterring fluid changes.
>>
>> Whether or not this helps I don't know, I just do
>> it as extra insurance and it's cheaper than the
>> blue stuff.
>>
>> I use the Orange since it is Ethylene Glycol, not
>> Propylene Glycol as the green stuff is, though
>> recently I found some green stuff that has
>> ethylene glycol. What gives?
>>
>>
>> Robert
>>
>> 1982 Westfalia
>> 1984 Westfalia
>> 1986 Westfalia
>> 1987 Jetta
>>
>>
>>
>>
>> --- gary hradek <hradek@YAHOO.COM> wrote:
>>
>> > It is likely that the coolant last longer than
>> > two
>> > years when you drive less.   I think the kind
>> > of
>> > coolant will influence cost of repairs if head
>> > coolant
>> > leaks are ignored.   Phosphate based coolant
>> > will
>> > damage the head more quickly than organic based
>> > coolant if the heads are allowed to leak for a
>> > prolonged period of time.   The posphate salts
>> > become
>> > alkaline and cause corrosion.
>> > This is not true for the organic based coolant.
>> >  As to
>> > the cause of head leaks I suspect heat and time
>> > will
>> > find a passage regardless of the type of
>> > coolant.
>> > Translation:   Coolant type or age of coolant
>> > does not
>> > directly cause head leaks but could indirectly
>> > cause a
>> > problem.   For example if the water pump leaks
>> > (old
>> > coolant)  and the engine over heats, this can
>> > cause
>> > the heads to begine leaking.   I prefer the
>> > orange
>> > stuff.
>> >   Gary
>> > Date:    Mon, 2 Jan 2006 14:46:32 -0800
>> > From:    rpc <populuxe59@YAHOO.COM>
>> > Subject: Re: coolant options
>> >
>> > Florian;
>> >   I concur with Dan.
>> >   I have a 1990 2.1 with 177,000 miles with the
>> > green
>> > stuff.  Just make
>> > sure you change it every 2 years. I have no
>> > idea what
>> > the previous
>> > owner did.  Westfalia.org used to have a topic
>> > on
>> > that: "clearing the muddy
>> > waters" and the author makes a good case for
>> > sticking
>> > with what we know
>> > (prestone) works and doing the 2 year maint.
>> > There
>> > are too many
>> > unknowns with the new "super coolants" in our
>> > older
>> > engines. I would use the
>> > VW blue stuff, but because of various repairs
>> > related
>> > to
>> > cooling/heating I could not justify costs.  I
>> > have
>> > noticed that the regular green
>> > prestone is no longer available so I bought 4
>> > gallons--should be good
>> > untill I need engine replaced.
>> >
>> >   Chris C  90MV
>> >
>> > "Daniel L. Katz" <katzd54@YAHOO.COM> wrote:
>> >   florian:
>> >
>> > any ethylene glycol based coolant sold at
>> > shucks or
>> > walmart is "safe"
>> > for
>> > the wbx. that said, the oem vw blue, as well as
>> > conventional types, may
>> > provide better protection from water pump
>> > cavitation
>> > erosion than the
>> > new
>> > extended life coolants. aside from their
>> > extended
>> > life, one advantage
>> > of
>> > the extended life types is that they do not
>> > coat metal
>> > surfaces,
>> > thereby
>> > facilitating heat transfer.
>> >
>> > back in 1998 i took over maintainance on a 1984
>> > 1.9 l
>> > with about 150 k
>> > mi;
>> > it had been using conventional coolant for many
>> > years.
>> > hearing horror
>> > stories of the then new dexcool gelling in
>> > older,
>> > perhaps dirty cooling
>> > systems, and problems with water pump
>> > cavitation
>> > erosion in pumps
>> > designed
>> > for conventional coolant, i decided to stay
>> > with
>> > conventional coolant,
>> > and
>> > encountered no difficulties, with now about 200
>> > k mi
>> > on the engine. at
>> > the
>> > time i took the system to be chemically
>> > passivated for
>> > conventional
>> > coolant chemistry, right down to the tiniest
>> > microscopic level.
>> >
>> > to avoid corrosion, the main thing is to keep
>> > the ph
>> > above about 8 (ph
>> > is
>> > 7 for pure water, 12 for new 100% ethylene
>> > glycol).
>> > low ph means an
>> > acidic
>> > solution, which is bad.
>> >
>> > today i use a 50/50 mix of conventional, green,
>> > napa
>> > brand ethylene
>> > coolant and distilled water for our 1.9 l.
>> >
>> > dan
>> >
>> >
>> >
>> > On Mon, 2 Jan 2006 01:20:35 +0000, Florian
>> > Speier
>> > wrote:
>> >
>> > >hi list,
>> > >
>> > >shopping for adequate wbx coolant starts
>> > confusing
>> > me. shops only seem
>> > to
>> > >have the all engines all makes prestone or
>> > similar
>> > coolant, and when i
>> > ask
>> > >if that is phosphate free, i get one of two
>> > answers:
>> > >answer a) if it does not say it is phosphate
>> > free it
>> > contains
>> > phosphate.
>> > >answer b) if it says all engines it is fine
>> > for
>> > aluminum engines and
>> > these
>> > >require phosphate free coolant, it follows
>> > that the
>> > coolant is
>> > phosphate
>> > >free.
>> > >
>>
>=== message truncated ===
>
>
>
>
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