@Spike555 Other than Mobil 1 FS Euro Oil, I haven't touched any of the Mobil 1 Vanilla flavors in over 15 years. The only others I use are their EP oils. Same goes for Castrol, it's either their excellent Euro oils or their Extended Performance oils. I believe that due to how certain Mobil 1 oils are blended, in certain engines, they evaporate faster than other oils. This is not a knock on Mobil 1. Castrol oils are made primarely with Group III and Group III+ base oils, and from what I understand they have higher flash points and lower NOACK than other base oils. Either way, Mobil 1 has revamped their formulations in at least a few times during the past decade. Some people have had bad experiences with AMSOIL, so YMMW.