Why does the Acura '09 TSX req prem gas when '08 Accord w/same 4 cyl engine req reg. gas?

The Accord '08 with EX-L pkg has a 4 cylinder engine that produces 190 hp vs the new TSX '09 from Acura that has the same 4 cyl which is tweaked to produce 201 hp. Maybe that's the difference in hp output with premium gas vs the Honda's regular gas. Hmmmm