R12 refrigerant

R134A replaced R12. Older cars used R12 and I don’t know the specific year but in the early to mid 90’s they switched from R12 the R134. To recharge a car that is R12, you either need R12 or a conversion kit (fittings) to convert your car. I don’t know how true it is, but some say that R12 worked much better but is harmful to the ozone.