>Freeze-12 is simply a combination of R-143A and some other >gases. It is >extremely uncommon to find service centers that support this, >but there >are probably some that will do a real R134 conversion for you. Earlier this summer I had my entire A/C blown out, cleaned out, and updated. The dealer suggested a converstion to R134 so I let him. It works fine, blows cold. I have to say I was never in a really hot situation and that my pickup with R12 does seem colder but unless you are in a hot climate, R134 should be fine. If its not, its an easy job to replace the oil in the compressor and recharge with R12. The R134 converstion seals will work with both. However that is not true if reversed. R12 seals will not work with R134.