Wow! What great conversation! You guys are in warp speed,light years ahead of the usual swamp rats. The undeniable truth about oils is , any organic oil is as dead as the dinosaur! Yamaha,honda,etc.recomends a ratio assuming you are using thier oil,however the after market does only one thing, improve lubrication. But you get what you pay for. I for one would never use less than the best,an ounce of prevention,etc!! Yeah, I miss the smell of castor, but I am told that Klotz,and Amsoil,have a delightful odor,maybe Redline also. And the protection quality is such that the ratio is 50 to 1.