Not true.  GM seems to like it, and it's been tested to meet a heck of a lot of
performance and corrosion specs.

From Sierra's info page -

"A recent General Motors service bulletin states, "It is our conclusion that
propylene glycol engine coolants will perform adequately under most vehicle
operating conditions" and that ". . .propylene glycol engine coolant may be
used in GM vehicles and will not affect the warranty coverage.""

"SIERRA Antifreeze has shown excellent performance in all aspects of the ASTM D
5216 specification (Propylene Glycol Base Engine Coolant) and in the Ford BL2-2
Dynamometer Test. Additionally, SIERRA Antifreeze meets all the corrosion
performance requirements of ASTM D 3306 and ASTM D 4985 (the primary
specifications for premium ethylene glycol antifreeze)."

And this is from the Amsoil site -

Meets the Following Corrosion Specifications

    * Federal Specification A-A-870
    * General Motors GM1899 (GM 6038 for non-aluminum
    * General Motors GM 1825 for aluminum
    * American Association of Motor Vehicle Administrators
    * Detroit Diesel Allison Div GMC
    * ASTM D 3306
    * ASTM D 4985
    * ASTM D 2570-96
    * ASTM D 2809-94
    * ASTM D 4340-96
    * ASTM D 1384-97A
    * SAE J 1034
    * SAE J 1034
    * Cummins 85T8-2
    * Ford ESE-M97B4H-A
    * TMS OF ATA RP-302A
    * AMC AM-4085
    * Freightliner

Meets the Following Performance Specifications

    * ASTM D5216-95 Automotive and Light Duty Service
    * ASTM D6211-98 Fully Formulated for Heavy Duty Engines
    * TMC (Truck Maintenance Council) - RP330 Heavy Duty Service

Corrosion test results

Corrosion weight loss, mg/coupon (ASTM D-184)

                          MAX ALLOWABLE TYPICAL
         Brass                 -10                  -4.3
         Copper               -10                   -1
         Solder                -30                   -.07
         Steel                  -10                    0
         Iron                    -10                    0
         Aluminum           -30                  +0.7

Aluminum Corrosion (ASTM D-4340)
         Aluminum           -1                    -0.3

Looks pretty comprehensive to me.

Tom

On 16 Oct 2003 at 18:19, Doktor Tim wrote:

> At 07:05 PM 10/16/2003, you wrote:
> Untested by the manufacturers and/or unapproved. In fact, not just the Euro
> marks but I have yet to hear of any manufacturer world wide that approves
> propylene glycol, no mater what else might or not be in there. Does not
> meet specs. Your experiment.
>
>

------
Tom Ring K0TAR, ex-WA2PHW  EN34hx
85 Westphalia GL Albert
96 Jetta GL The Intimidator
taring@taring.org

"It is better to go into a turn slow, and come out fast, than to go into a turn fast
and come out dead." Stirling Moss