FYI - May 07, I had a leak. My mechanic used dye to find the leak, replaced a couple of o-rings- simple. Then instead doing a complete conversion, we went with Freeze 12 - it is a substitute, environmentally friendly, and cheaper. I just pulled the repair order. 5 cans of Freeze 12, 2 o-rings, locate the leak, vacuum the system, and I remember telling him to add a little more oil than normal, which he agreed was ok. No problems since. Freeze 12 does not get quite as cold as it's predecessor, but I can't tell any noticeable difference. Freeze 12 is on ebay.