Does this car have to run on premium 91 Octane gas?

You probably don't have to use premium, however I would suggest using a higher grade just because.

The manufacturer requires the higher octane gas, either 91 or 93. Using anything less is like the equivalent of putting Folger's instant coffee in an espresso machine.

If your manual says recommended then no you do not need to use Premium Gas. If it says it is 'required' then you do. Consumer reports did an extensive study on octane, specifically with Acuras and determined there was no change in performance or fuel economy. They contacted Acura and they admitted that the NSX is the only vehicle that requires higher octane because of its higher compression. According to two studies I have read on this you can easily test if there is a problem by putting in half a tank of 87 octane. If you do not experience pinging or a loss of performance then you are fine. Octane is just an anti-knock additive. It does not burn cleaner, provide better performance or provide better fuel economy. I have been using 87 octane in my 2006 Acura TL since the day I bought it and it still runs perfectly.

Can I use 93 on my 2002 acura mdx