Over the past weekend, I converted my 300SD back to R-12 from 134. Complete flush and evacuation, to be sure all traces of PAG were removed. New receiver/dryer, with the proper switches replaced with new. The compressor is also new, replaced when the 134 conversion was done, a few thousand miles ago. My '83 SD is the first MBZ I've owned. I've owned and driven many, many cars and trucks. I have never seen air conditioning performance like this car. On MAX AIR, within a few minutes from start up, the car actually becomes uncomfortable. The longer I drove, the more I found the need to "warm" the interior. Truly awesome performance.