Well I would suggest getting a tow tune for the weight of the trailer, you are pulling. And if you are wanting to run 89 octane then I would suggest 89 tow and 89 performance. And just let bill know on the form what you want out of each tune. i.e. your driving conditions and if you rather have more power or more mpg or both. Then if you only want 2 tunes I would just leave the 93 perf. incase you ever want to try it out. But you may would want to keep the tranny only tune