old thread,....so what,.....there are new people on this forum everyday, that may have questions about this issue.
I've used Marvel Mystery Oil in every engine ( both air plane and briggs kart racing engines) I ever used as an after run oil, and never had any problem. sometimes, people make too much of an issue (over thinking) about details that don't really matter. a lot of what is put on packaging, is put there to protect the manufacturer from law suite about any and every little potential problem...... they need to think of just about anything that the consumer might do with their product. Big insurance companies have people who do nothing but think of things that their clients might be sued for.