Quote Originally Posted by NightFlyer View Post
Again, HC-12a is a generic term, with the 'HC' simply meaning hydrocarbon. It's just an identifier, and doesn't signify anything more. Basically, the reason for the discrepancy in FrostyCool's advertising of their 12a cans is that the cans are designed for use with R-134a can taps and fittings, thus why they proclaim it as being for a "retrofit" system. But the actual refrigerant in the can is essentially the same as any other 12a hydrocarbon refrigerant.
This may well be true, but not how it reads to me, as I said. And I could not find anything similar to what seems to be your logical opinion/conclusion. In fact, I just read it all again and it says, "FrostyCool 12a Replacement Refrigerant along with mineral oil are Incompatible with butyl rubber hoses". That covers a lot of R-12 systems running around (incompatible)! I suspect FrostyCool is a HC-12a based product but has other things in it making it this way, or, the first link is wrong about it being a drop in. It may be the best thing ever for other systems, including conversions. Dunno, don't care, it's not worth any added risk, the price difference, and certainly not having pressure data for individual vehicles/systems when it comes to diagnostics later! (Or going on about ;-)