Better known as Freon, R-12 is an awesome refrigerant used in automotive air-conditioners and refrigeration applications. If you happen to own/drive a vehicle with an air-conditioner that is factory charged with R-12 Freon, and the systemworks good and does not leak, DO NOT UNDER ANY CIRCUMSTANCES MESS WITH IT. Pretty much any vehicle manufactured prior to 1993 is guaranteed to have an R-12 A/C system, but some 1993 vehicles came with the new stuff. It all depends on the manufacturer. Any vehicle manufactured prior to 1993 is guaranteed to have an R-12 air-conditioning system from the factory, with some exceptions. I have seen 1993 vehicles with R134a and early 1994 vehicles with R-12. Dichlorodifluoromethane (R-12), is a colorless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol/Clean Air Act, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. R134a is R-12's replacement, and has been used in automotive and refrigeration applications since 1994-1995. You will begin to realize that R-12 is the superior refrigerant when you are idling in a parking lot or stuck in a traffic jam. While an R-12 system will almost always blow cold air no matter what, R134a begins to blow merely cool air when the vehicle is not moving.
True stories of R-12's superiority:
The A/C in my dad's 1983 Toyota Celica was absolutely freezing! Gotta love that R-12! The air-conditioner in my mom's 1990 Toyota Camry was the same way, as was the A/C in my dad's 1992 Dodge Dakota, and in his 1993 Chevy S-10 Blazer. R-12 is just a far superior refrigerant to R134a.
A friend of mine put some cans of soda in his old 1980s fridge that uses R-12, and the soda got so cold and frosty that some of the cans actually burst!
R12 was a planet in the Star Wars comic series. R12 was best known for producing a unique gas, also called R12, that was the most potent refrigerant known to the galaxy. R12 gas became obselete when the planet R12 was destroyed by the Death Star.
<Han Solo> Quick, Chewie, grab a can of R12 and recharge the A/C system.
<Chewie> (unintelligible reply)