I don't see any post about comparisons of different performance enhancements; ie: Cold Air Kits, Throttle Body Spacers, Mass Air Flow Meters, Exhaust Systems, Hi-Flow Cats? There are plenty of upgrade parts available any body tried any of them? Think any are better than the other? I have an 08 PF with the 4.0L and I was looking at adding the K&N Off Road Air Filter Kit with the AFE Throttle Body Spacer and the JET Power-Flow Mass Air meter, should be good for an additional 20Hp but fuel economy is what I'm really after. Any fuel economy tips?

Over at cleanmpg.com, the hyper milers found that cold air intakes give more HP but less MPG. They should know. Also drive slower… You’re driving a brick.
I am led to understand that an intake spacer by poster “highaltitude” [See final post of 10/23/2010] improves HP & MPG: http://www.thenissanpath.com/viewtopic. ... ake+spacer
I purchased a Volo performance chip model FS3. It accesses the computer thru the OBD II port. I get slightly better MPG than without it.
I pump up tire pressure above rating on door. Some tires roll better than others [Michelin is a good one]
The transmission needs to be above 40-45MPH for the torq converter to lock-up, then better MPG’s happen. Otherwise it is a soccer mom’s slush-a-matic SUV. Also it does not go into “fuel shutoff” when coasting down a hill. There are times I throw it in N and watch the MPG readout climb.

These are some of my observations after 1 ½ yrs of ownership. It replaced a 98Tahoe. Not only is the PF not so massive but gives me 15-20% better MPG. I, for one, wish it had the 6sp MT as found in the Frontier or X-Terra.

CPLTECH wrote:Also it does not go into “fuel shutoff” when coasting down a hill. There are times I throw it in N and watch the MPG readout climb.

My MPG readout max's out when I go downhill. Have you read somewhere that the fuel doesn't shutoff with no load on the engine?

CPLTECH wrote:There are times I throw it in N and watch the MPG readout climb.

AC on/off ?

Sorry that I did not explain myself better.
Most of my driving is about town and on those downgrade speeds of ~45 or less, it appears the TC is unlocked. Guess I need to buy a ScanGaugeII that shows instant MPG & more. Had an Australian kit on the old Tahoe & loved the info it provided.

I must say that the transmission is where the engineers went overboard in design when it comes to the fact that the TC is constantly in a state of percentages until full lockup in 5th only when conditions are met. I liked my Tahoe that would either be unlocked or locked in 3rd & 4th . Extremely advantageous if towing. And I am yet unconvinced that this constant varying of the TC helps my MPG any. It bothers me to such an extent that I will be looking at other brands when this one outlives its usefulness. If I was a mechanic with time on my hands, I would go out and buy a wrecked XTerra or Frontier with a MT and swap it out… I dislike this trans that much.