OK here's my .02 I've been flying gassers since 1985 and used Amsoil at 1.5oz's to the gallon ( around 90-1) and never had an oil related failure, as a matter of fact no failures with the exception of a too lean run on my BME 102 (my fault) so I'm sticking with what works for me. I have tried Pennzoil, Redline, Lawn boy and Bel-Ray, but always went back to the AMS