Our NAH is garaged and it doesn't get very cold or hot here. However, I do make short trips at least twice a day. I have to read some more but how does it affect emissions and the cat converter?

It ought to reduce emissions since as I suspect the initial gas engine startup is likely for the same purpose as it is on the Prius, to get the catalyst up to operating temperature to reduce emissions. (FWIW, the NAH shares some/most (?) of the same quirks at the Prius such as keeping the ICE running to provide cabin heat.)

You might find http://www.techno-fandom.org/~hobbit...ive-stages.txt and the PDF http://priuschat.com/forums/knowledg...rence-aid.html interesting.

IGN values are standard on http://www.scangauge.com/ and you don't need to know (have someone figure out and publish) the X-Gauge values to display it. Since the 2.5L engine is totally different than the 1.5L on the Prius, I'd expect the IGN values to be totally different.

On a side note, the slides starting with http://john1701a.com/prius/presentat...ntation_38.htm talk about the thermos that the NAH doesn't have. On the 2010 Prius, the thermos was ditched in favor of an exhaust gas heat recovery system that supposedly is even better at warming up the engine. (I'm guessing that part of it was cost and that the thermos coolant pump sometimes screeches or fails.)

06 Toyota Prius, 04 Nissan 350Z; mom has 07 NAH