Hotsaws 101 is full of it!! This has all been beaten to death a million times, all angles have been looked at and discussed, we all have a good understanding of what's what, you're not providing any unknown information. Oil does more than just lubricate! Ultra is bottom of the barrel, burns very dirty at any ratio, It lubes OK though. The fact you have carbon issues should answer the question, the answer is right in front of you. Who ever told you 40:1 will make less power is in the business of selling new saws, not making them last or make more power. Pretty much everyone here recommends 40:1 or 32:1 so I don't know what you mean buy learning to run 50:1 from this site. If you start looking for an new car and want to know how good the engine is you ask an independent mechanic you trust, and do as much research as you can. What you're doing asking the salesman, you're listening to the salesmen, instead the mechanics and in some ceases engineers. They want you to believe they know all, when all they want is you to buy overpriced oil and a new tool as soon as possible. Some love Kool-Aid.