[jeepster357]

I use the Airaid cold air intake along with the Throttle body spacer, I cant quote you numbers but judging from my seat dyno (seat of my pants) my 4.0 does seem to have more oomph. I have noticed haveing to down shift less on steep grades and I did gain around 1-2 mpg's. And there is a added bonus of a little bit of a "growl" that comes from the air intake. cool.

	Throttle body spacer A throttle body spacer is designed to improve the quality of the airflow, allowing air that is more condensed and, thus, more oxygen laden, to enter the combustion chamber. The result of this is a more efficient burn, which serves to release more energy from the fuel, making more horsepower available.