With 3 VWs that have Freon12 A/C systems I decided this was the year to look 
at converting to other refrigerants. Since VW has a bulletin on converting to 
R134a I expected to do that, but my experience with the Eurovan R134a system 
hasn't been great. R134a isn't as efficient in cooling, and runs at higher 
pressures on the compressor outlet, loading the compressor, clutch, belts and 
engine more. (Even though the Eurovan has marginally more power, it bogs down 
something awful in the summer when the A/C kicks in.)

The shop where I've had my A/Cs serviced did R134a conversions last year on 
older cars, but stopped because there were too many problems with them after 
doing the conversion. They often had to go back and replace the compressor 
clutch, hoses, or compressor, and the customers keep complaining that they 
don't cool as well. (Texans take their A/C seriously.)

Instead I'm trying converting to FR12 (FrigC) refrigerant. This is an EPA 
approved, non-flammable, low-toxic blend of refrigerant gasses that comes very 
close to R12 in properties and requires minimum conversion. Basically the R12 
is evacuated, adapter fittings are attached, a small amount of oil is added 
(without draining and changing the compressor oil), and the system is charged 
with FR12. It's generally a lot cheaper than a R134a conversion.

Pennzoil distributes it, and it's claimed to cool as well and work as well in 
older systems as R12. You can check out  www.frigc.com and find details and 
installers for your area.

So far I've had it put in my '87 Westy, and it's going in my son's '86 
Cabriolet today. First impressions are that the claims are true - but I'll 
update my experience as the heat of the summer gets here.

Looking at the MSDS for the stuff there are some details not in the website: 
It's a blend of 59% R134a and 39% R124, with 2% Butane. (Please, no messages 
about "butane bombs" - with only 2% butane in the mix it is impossible to get 
a flammable mixture in air. Some people HAVE tried to sell pure Propane as a 
refrigerant. It does cool great, but flammable refrigerants are against the 
law, and could cause fires or explosions if there is a system leak.)

R124 is actually a "chloro-flourocarbon" and is alone is classed as 
ozone-depleting, but it is allowed and approved by EPA in this mix.

I hear there are a number of similar blends on the market now for older cars. 
This is the first I've been able to get much information on, and with its 
national distribution system it looks pretty good. 

If you find another that gives good results let the list know.

Tom Brunson
'87 Westy
'91 Carat
'93 EV MV
etc (to ex '58 Borgward Isabella Kombi)