Personally, I think hydrocarbon refrigerants (HC-12a, Duracool) are a good choice for refrigerant.... very popular in Australia. The only thing that would keep me from using it is if:

1. You live in a state where it's banned.
2. You don't do your own automotive repair. (HC refrigerants will contaminate recovery systems).
3. You're worried about insurance ramifications in the unlikely event you're the first person that has something disasterous happen to them.

There have been no documented cases of fire disasters with this refrigerant in the car. I would leave your car the way it is and enjoy the cold air.

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95 E320 Cabriolet, 169K