[ac97gt]

used cars usually come with the manual, but you never know what the previous owners may have done with it. a car that new should have the manual. 95mustanggt he wasnt using 97 octane it was a 1997 neon with 87 octane. we have a 1997 neon too (funny enough) that runs only 87 octane and is perfectly fine. its my sisters car so i could care less and didnt read the manual, but im sure it says to run 87. my mustang says to use 87, but ive only ever put mobile 89 in it. peace of mind i guess. when my dad fills it he uses 87, and i cant stand it. its all in my head im sure.. but i seem to get worse gas mileage for some reason (by the numbers).