Yeah I had done some searching prior to the post and had found the information on the Cold Air Intake and the computer chip. I wanted to see if anyone else had some other experience. I have only had the truck for the last 20K miles and it has only been really sluggish the last 10K or so. I guess I have always noticed a lack of performace at higher speeds. Also, I had driven a Pathfinder with (what I thought)was a similiar engine and noticed a major difference.

As far as the gas I have read in a ton of places that you should put Premium in the Xterra. I was told that by a Dealer and also read a ton of reviews that said the same thing. I thought it was BS until I took a trip and saw a major difference in MPG from the tank of Premium and the tank of Regular. I normally put in Mid-grade but lately I have put Premium in and it has drastically increased MPG and the engine runs a lot smoother. My friend with the Pathfinder was told the same thing when they bought the vehicle and has noticed the same results with Premium.

http://www.carreview.com/cat/automobiles/suv/nissan/PRD_134_1524crx.aspx