AMSOIL in Lower Unit

I drained my lower unit yeasterday from Lucas 80-90 to Amsoil 80-90 Synthetic gear oil. I **** you guys not, I gained 300 RPMs. Now witha Yamaha 150 2 stroke with a 17x15 1/2 ss prop, I went from 4900 RPMs to 5200 RPMs and a gain to top end. For all that is holy....you have to try this stuff. It is marine grade and will mix safely with 10% water and still protect those expensive machined gears....Dirk