First I have read just about every thread on this subject, so I know there are folks out there who would never do this. This has been a BRUTAL summer in South Texas and lots of other locales. In 2004, I had my 1985 300SD converted to R134a at my favorite indy shop at that time due to a leak repair and the high price of R12. Well, it never was great at cooling after that, but adequate. This summer, I just could not deal with temps in the car. I was getting at best 55 to 65 degrees at the vent at 100º plus temps. I had started driving my V8 w208 which has very cold air as a daily driver. But I missed my SD. So...about a month ago, after doing tons of reading on the subject, I ordered two cans of "Enviro-Safe R134a Replacement Refrigerant with Dye" after being strongly discouraged by my present indy. He agreed to evacuate the R134 from my system, but told me he wouldn't work on my a/c again due to contamination. So I put the two small cans, 5 or 6 oz, in myself. I got a low pressure reading of about 30 from those two cans. On the way home, I was BLOWN AWAY. Vent temps began plummeting...(at about 95º outside) they fell to 45º on Auto fan speed after about a mile of driving. WOW! It got down to about 40º by the time I was home. Today, at around 11:30 with outside temp around 91º, I had a vent temp of about 35 DEGREES on low fan!!!! I wasn't running around with a vent thermometer when I had R12, but I don't ever remember it EVER being this cold. Maybe I made a mistake doing this, but it's an old car and it will die with me...not sure who'll go first. ONE OTHER THING...I can BARELY tell when the compressor comes on. I mean I push the a/c button and the idle speed barely changes. With R134, I could feel the hit of the compressor coming on. Just wanted to share my experience. Didn't think my old SD could ever have air this cold.