I havn't used Amsoil but I do use another brand synthetic that mixes at 114:1. If I go much below 80:1 It gets kinda stiff when starting it up after sitting a day or more. The 100:1 mixes probably start with a high viscosity base (mine does) so going much below say 75:1 with 100:1 Amsoil might not be such a good thing. I'm happy and convinced mine gives me piece of mind mixed at 80:1, and there is a slight power increase and crispness to throttle response over mixing at 114:1. These synthetic companies are in a contest to have the oil that protects at the highest ratio possible, a bit more oil can't hurt. And just in case the company is full of b.s. you are protected.