I'm not considering R134. I'm talking about R416a which is a blend containing R134. The company says: Patented blend of the refrigerants R134a (59%), R124 (39%) and R600 (2%), which is formulated to closely match the thermodynamic properties of R12. Listed as SNAP acceptable by the US Environmental Protection Agency (EPA) for use in all mobile applications and has achieved Underwriters Laboratories (UL®) classification. FR-12 refrigerant is a low cost solution to the expensive and environmentally hazardous use of CFC based refrigerants. FR-12 is right for the environment, right for the equipment and right for the budget. A drop-in refrigerant designed to replace R12. ASHRAE A1/A1 safety designation. Non-flammable, non-toxic. Lower system operating pressures resulting in lower leak rates and discharge temperatures. Closest pressure match to R12. Compatible with Mineral, Alkylbenzene, POE, PAO and PAG oils, depending on the application. Recoverable and recyclable. Can be topped up. Produces faster pull-down times and is less susceptible to system failure under high ambient conditions. Sounds good to me.