I just got my NX2K running recently, and im getting horrible mileage!!! my last tank got around 180 miles on 92 oct, and now on 89 oct im heading for around 190 or so. I dont romp on it too bad, but i do let it warm up in the morning, what are your cars doing? My brothers 92 sentra se-r is completely stock and its only getting around 200 miles to the tank. Are my 17" wheels a factor in this at all? i only have a pop charger performance wise.