I have read the problems GM had with Dexcool... an  OAT formulation...
were with cast iron block engines. If the cooling system is allowed to
run low for long periods of time a sludge forms from iron surfaces in
the vapor zone, i.e., not in constant contact with liquid antifreeze.
The sludge builds up in heater cores and engine passages.  This was
compounded by a radiator cap that easily plugged and, among other
things, wouldn't draw back the overflow so that a casual check of the
overflow tank would make you think the system was topped up.

Their 4.3L V6 was especially prone because it had passages real high
on the engine compared to the radiator, so if the level is even a
little low sludge could form.  

Another problem occurs when large quantities of silicate antifreeze
are mixed with Dexcool for long periods( years) in the system. The
silicates can fall out of suspension over time forming a jelly.
That's rare though and easily controlled.... first,  make sure you
flush well at change over, or change it again in a year (as you should
anyway if NOT using an extended life antifreeze).  Finally,  even half
decent shops now recognize the orange color of Dexcool and use the
correct top off.

AFAIK, all Japanese coolants are low in silicates.  Several European
mfr's use a hybrid coolant (OAT and phospate or somesuch) making them
both low silicate and extended drain.  However, most shops do not
recognize or stock all the myriad of colors... blue, pink, yellow,
tangerine, etc, so you'll never be sure unless you always carry some
with you.

Finally... in several articles I've read, OAT antifreezes performed
as well as high silicate formulations in all aluminum systems, it
lasts for a long time... actually much longer than the 5 years
indicated... and doesn't pose the risk to water pump seals.  I use
OAT, but only when I know i can get a good flush first.  But I'll
never again use Prestone in my Japanese car... it's either OAT or a
Japanese formulation.

BuddyWh

I agree. Regular antifreeze has worked just fine for decades with regular
change intervals.

The "mud" comes from contamination.  Either the old-type coolant
didn't get flushed out well, or else the level of Dex-Cool dropped too
low, and air got into the radiator for an extended period of time.
Texaco recommends you overfill the coolant bottle to the extent
practical.  You also should remove the radiator cap (with the engine
cold) and visually check to see that the radiator is completely full.

I have seen photos of the orange mud created when air gets into the
system.  I doubt that the radiator can even be rodded out; it looks
like a replacement would be necessary.  And of course getting the mud
out of the engine itself is just about impossible.

Dex-Cool is long life stuff, but is not "maintenance free", in that
you must keep an eye on the coolant level.

JM

   Having just purchased a couple bottles for use in my Max, I wondered the
same thing.  The generic coolant I bought contained ethylene glycol,
diethylene glycol, and distilled water.  A look around the Autozone showed
others with these three ingredients plus silcone silicate, and others.  I
concluded that if silicone silicate isn't in the content list, it's safe.

   Dave

Zerex G-05 is low phosphate, low silicate, but not NO silicate at around 250
parts/million.   It is "hybrid organic acid technology" (HOAT), FWIW.  It's
compatible with 'regular' anti-freeze, but the manufacturer (Valvoline)
recommends a good flush and a clean system if converting over to it.  It usually
says "Ford/Chrysler compatible" on the bottle.