Thats very unlucky that you only have acces to 91, i run map 2 with no issues using 93, youre going to have to log and have terry or some other people smarter than us check to see if you can run map 2 on the 91 thats available to you. as far as octane boosters, its not necesirally horrible to use every know and then to have some fun or to track. you can also use unleaded race fuel like sunoco 260GT, which some sunoco pumps have, check their race fuel finder to see if you have any in the area, and again log and make sure the car likes it before doing it to often lol