Yeah i always used 87 fuel with my 91 runs great with 87 but i just resently put a full tank of 93 octane because the gas station only had 93 and i was low on fuel extremely to the point where i couldnt get to another place and I can feel the difference because my car just resently started to have a little trouble in cold starts and doesnt run as smooth i am trying to run my tank all out and then fill it up with 87 from 76 station.