Flammable refrigerants are illegal. Non flammable blends cause problems whenever a leak occurs. The different elements leak at different rates necessitating a complete recharge.

I suggest that you look around for a deal on some R12 like Jim did.

Steve Brotherton has wisely pointed out that R12 is the least expensive component in the a/c system.

The other reason is that with all these alternative refrigerants being put in cars all over the place, it is accidentally getting recovered into containers of R12. This contaminates that entire container and requires it to be destroyed. The only R12 we have is what is on the shelf yet to be sold and what can be recovered. Every time an alternate refrigerant is put in a system it opens one more chance that it may contaminate our remaining R12 supply. Please don't do this.

Most of these fancy named alternatives look too good to be true. In my experience when something looks too good to be true, it usually is.

My $0.02,