Other threads on here have shown that you can run on a lower octane. I have owned 2 MDXs and run mid-grade (89) in both with no issues.
The 2006 Acura MDX runs on premium unleaded (required).
The 2006 Acura TSX runs on premium unleaded (required).
The 2006 Acura TL runs on premium unleaded (required).
No, you don't have to. I use regular fuel in my 2006, and it continues to get a clean checkup every time I take it to a body shop.
Premium Fuel 91 octane.
The 2013 Acura RDX runs on premium unleaded (required).
The 2009 Acura MDX runs on premium unleaded (required).
The 2012 Acura MDX runs on premium unleaded (required).
The 2004 Acura TSX runs on premium unleaded (required).
The 2014 Acura TL runs on premium unleaded (required).
The 2008 Acura TSX runs on premium unleaded (recommended).
The 2010 Acura TSX runs on premium unleaded (required).