Why Tower??? You can find fuel at your LHS for A lot less money. I run Power Master 15% with 18% blended oil in everything from 1/2A to the YS 1.40. Most manufactures say to use A four stroke 20/20 blend. I can't recall who makes the fuel for Tower, I think it's cool power but someone will correct me. If so then I think it's A 17%synthetic oil?? I have two of the Saito 100s to break in and run this weekend, like all my stuff they will get the Power Master 15% and love it. When in doubt read your engines instructions and go with what they say to use.