Filter and Intake System

[Ultramag]

What would the real benefits be if I installed a Intake System and Filter kit like K&N.  I would be putting this on my '06 Unlimited, Automatic 4.0L.  I have heard that it really improves horsepower and gas mileage.  If I was lookinf for more horsepower then I wouldn't have bought a Jeep with a 4.0  but I wondered if any of you knew of any other benefits.  How much would one of these help with MPG?

[LoneWolf]

When my jeep was stock I got 18mpg at the most... .20mpg if I kept it under 30mph  , all with no throttle body spacer and a stock filter. Now with 35's I've got an AirRaid intake and throttle body spacer and Flowmaster 40 on my 05 Rubicon. I get 13mpg; with my foot in it all the time and 15mpg driving like Miss Daisy. The increase in horsepower and throttle response was VERY noticeable. Never been dyno-tested but I know by driving that it increased my HP considerably. why do it? More torque = better performance. The 4.0 is no wimpy motor by any standard; stock or slightly modified. They produce alot of torque and HP... but if you can squeeze some more out.. why not?

[Ultramag]

Great points.  I will definitelty do this in the near future.  I have a couple more things I want to do on the outside first, then I will do this, which I am almost done buying add-ons!!  WooHoo!!  (Wife is glad too! Ha)  Would it make a differance if I bought a K&N filter for it without the intake system or would this be a waste of money?

[LoneWolf]

no it wouldn't be a waste and only cost about a 1/4 of the money of the whole system. I did that at first too, ran just a K&N in my stock air box for about a year. I also took off that "HORN" from the air box which just restricts airflow.