DanC
Well-known member
When I changed the coolant in my 93 LT1 last August, I was able to purchase coolant that met the General Motors spec 1825-M5 that's noted in the factory service manual for this engine.
Just got back from shopping for coolant, and the specs on the package now are mostly "Meets ASTMD-3306 and ASTMD 4985".
Found one that also had "GM1825M" with the others (the 5 is missing at the end, significant??).
With all the horror stories floating around about DexCool and others with compatibility problems, what do I use to top off the system?
Are the new specs similar to motor oil ratings? Backward compatible?
I'm so confused...
Thanks,
Just got back from shopping for coolant, and the specs on the package now are mostly "Meets ASTMD-3306 and ASTMD 4985".
Found one that also had "GM1825M" with the others (the 5 is missing at the end, significant??).
With all the horror stories floating around about DexCool and others with compatibility problems, what do I use to top off the system?
Are the new specs similar to motor oil ratings? Backward compatible?
I'm so confused...
Thanks,