The Pathfinder is the "premium" mid-size SUV offered by Nissan. You can't have the "premium" model being the same or even upstaged by the "lesser" Xterra. It's just marketing.

You can't tell, feel, smell, or taste the other 5 hp anyway. You're talking less than 2% difference at the uppermost Hp peak. Leaving the spare tire (and it's dead weight) at home would do more for the performance of the truck than getting that 5 Hp.