[Jay McGrath]

Based on the fact my 1986 Porsche 911 engine label states 39 oz of R12, I simply divided by 3 and the result is 13 oz of Enviro-Safe. I initially evacuated the system to check for leaks and then added the first can, started the car and put the AC on maximum then stated the car and added the second can (each can is 6 oz). I did not add the additional oz as it is too hard to add one oz with a six oz can. Just as an update, at 2000 RPM the temperatures have dropped to 38 degrees F. I have never had it this cold. I am sort of sold on this stuff as a replacement for R12, it works. Additionally, I had the car serviced and charged with R12 (very expensive) and never got this cold. I think the best I ever got with R12 may have been in the low 50's.