Talked to this guy today, and he said he used some kind of Amsoil synthetic engine oil and he only changes his oil every 25,000 miles. He said every 12k or so he sends in a sample of the oil to Amsoil and has a test run on it and they always tell him it is still good and should keep running this stuff. I have a hard time believing any oil will go 25K. just wondering if any of you have any info. on this miracle oil? Sounds kinda strange but who knows.