The QX56 requires premium fuel, that is where the extra 10 horsepower comes from.. yes, computer fuel curves are different, BUT ours adapts to premium fuel, so same gains should be attainable.
Re: the 4.5 L V8 found in some of Infiniti's cars: I was told the same thing, that the Titan shared the same basic block design as the "45" models. After doing some reading of articles by Nissan, it was stated that the Titan 5.6L was built especially for this US vehicle from the ground up. Nothing was recycled, but some ideas and principles slipped through I am sure...
The first article I read about the Titan before I bought it, in December, can't remember.. one of the mainstream publications ... claimed that the engine was derived from the above mentioned, but that was later dismissed.
Not quite sure what to believe, except I like my Titan alot no matter how the engine was conceived.
