EDIT:
Ooops i mean to quote the below:
I am not sure if my FAL soft-start makes it last longer. My controller starts at 60% and increments up to 100% if the fan-speed is not cutting the cooling neccessary.



I am getting 18 MPG with all my mods now:
S&B CAI
Magnaflow 'FireStarter' Exhaust 16614 (dual out rear)
Edge Evolution (level 2 canned)
Running on a 4.6L 4x2 SCREW 3.55 and 275/55-20

 

I dont think buying a CAI will increase fuel economy by any noticable difference. I remember I bought an intake for my old vw and I actually lost mpg because I loved the awesome sound it made when you hit the gas. Ive toyed with the idea of performance mods, but for economy and reliablity's sake ive decided to leave it alone. Lets face it, the 4.2 is a good solid motor with decent torque, but is slow as a stone. Apprieciate the truck for what it is and what it was designed for. I say if you want to go fast, get a different vehicle.

 

I don't think I can agree with "slow as a stone" - I really don't have any complaints with the performance of mine until I load the bed to the rails and hook up a trailer. The 4.2 is every bit as powerful as the old 5.0 V8 was not that long ago. It's a TRUCK, folks - if you want a vehicle that performs like a high performance car and looks like a truck, go find a good used Lightning or something like that.

I can load mine to the rails and attach a 5x8 enclosed utility trailer and load THAT to the gills and get 17.5 MPG on level ground with the cruise set to 64. Just that there impresses me.

 

I use to get an average of 14 mpg until I put a CAI, xcal II, and the E fans on. Now I get 19. All this totals to $800, and 105 miles more on 21 gallons of gas.

 

The xCal II probably made 80 percent of that 14-19 difference.

 

went to 16 with CAI, then 17-18 with Xcal II on 91 performance, then with the fans I get between 18-19 pretty steadily, But these hot summer days are not very friendly on my mpg.

 

I agree. I think a CAI is best for an internally modded engine that really breathes. I am not saying you may not get any increase but for the perf increase/cost, it ain't happening.

Either way will all mods, my MPGs have increased. I would have bought that vs a K&N filter but I like the S&B's better.

 

I think I need to check my mpg now because I dont know what its like now that I have headers and no exhaust (soon to change).