I intend to keep using the ‘correct’ fuel for my car unless I have a reason to do otherwise, and obviously the $2 per fill up won’t bankrupt me. And as many have stated in this forum, use the lowest octane that your car will run well on, and there’s no benefit in using higher octane than this. Filling up every-other time with 89 when my car runs fine this way seems to me to be just being intelligent about it, not cheap.
However, my question was is it possible to use xylene as an octane booster, and what if any consequences should I expect. Telling me to use the fuel that the owner’s manual specifies does not answer my question. So far, jtsanders has come closest to a useful comment, no offense intended.