The definitive answer is I use 134a and some of the Prius and in a few I use this HC12A It's a hydrocarbon blend of gas that can replace r12 and work in a 134a system I have it in both applications and I've had no trouble since I've been using it the HC12A I've been using since the original r12 scare back in what 85 something like that when r12 shot up to $60 a pound I was buying HC-12A for 5 a pound
