Hi group,

I have a civic 05. My dealer told me that I could just use 87 gasoline
as fuel. I followed his advice and have been using it for four months.
However, this morning when I checked the user manual, I found that I am
supposed to use 91. It amazed me since in my mind 91 is for luxury car,
which my civic apparently is not. Is there any deep reason why Civic has
to use 91? I'd appreciate if you could share me your thought.

Thanks,
Doug