I finally bought a K&N Filter a couple of days ago. I don't really notice any power boost but what is much, much more important to me was the fuel mileage so I'll have to wait a couple more days to see if it improves it. Although, I don't really floor the gas much cause when I drive my truck, I become Lightfoot so maybe that explains the no noticable difference in power. But I am still wondering, on the average, how many mpg's and hp's can a K&N filter add to a 99 F-150 4x2 with a 4.2 V6? How about a Superchip which I am planning to buy later on? I am hoping to get to the 20 mpg in a tank of gas. Right now I get 17 mpg mix with 75% on highways (does city driving burn that much more?). By the way, to those people who are being belittled for having a dinky V6, don't worry buddies V6 are adequate and are not underpowered for normal jobs, and keep in mind that these are full-sized trucks not Mustangs. With that in mind, I am still wishing I should've sprung for the 4.6l.

Leo dC

 

I do not think you will see any noticable difference in hp or mpg by just changing to a K&N filter. The superchip is the only mod that I could really feel a difference in performance. I still think the other mods I did are important and increase performance, but I honestly could not feel much of a difference. I would definatly recomend getting a superchip.


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'99 F-150 XLT SC 4x4 5.4L Auto 3.55LS Tow pkg skid plates , Superchip, Gibson cat-back, K&N filter w/ airbox mods

 

Good Guy, The K&N claim for just the filter is about 5 hp. On a 200 plus hp engine you probably wouldn't feel it. This was the first mod I did and I couldn't feel any difference. I did an air box mod, opened it up, still didn't feel anything. Don't feel bad, the K&N is a lifetime filter and supposed to do a better job than stock.

The mod that you can feel immeadiately is the superchip, about 20 hp on the 4.2. I didn't notice any mileage improvement with the K&N but am getting about 10% better with the superchip, but you have to use premium gas. From what everyone says on the boards, after the chip, the next most effective mod is a performance exhaust.

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98 Nascar Edition, superchip, K&N with airbox mod.

 

The first change (mod) I did was a K&N filter. I saw absolutly no change in HP or milage. But when next I added the flowmaster cat-back exhaust I could really feel the HP. Not much change with milage though. And then I finally got the chip. WOW!!! BIG improvement in HP and much better milage too. Even though that first mod didn't show any improvements in the beast, IT really does help the exhaust to do a better job.

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97F150 XLT SC 4x4 Flairside 4.6 V8 5sp Dk Toreador Red, 3.55LS
ARE tonneau cover, p255/70rx16 tires (came w/235), Superchip
Pioneer CD w/4 Polk Speakers & Clarion APA5240amp, skid plates
bed liner, side window deflectors, reese hitch, K&N air filter
40s-2chamber Flowmaster, Bosch +4 spark plugs, rustproofing
Better Built Stainless nerf bars

 

Good Guy,

I just installed an Airaid FIPK into my truck. I haven't had it long enough to notice any fuel mileage improvement (and can't really tell until I get the odo fixed) but I did notice a significant jump in seat-of-the pants performance! No hard numbers, and I'm not all that much of a speed demon, but I am after better mileage and a little more "umph" when I have to pass that other guy on the freeway.

I plan to go with Flowmasters next (just a muffler swap for now) and will look for any MPG gain there (as well as even more "umph")

BTW, the Airaid gives a sweet sound to my engine at 2,000+ rpm, and at WOT, it sounds like the good ol' days of 4 barrel carbs on a big block. Grin quotient very high!

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Cam

'98 F-150 SC XLT, 4.6L, Bright Red, Red Spray-in Liner, Extang Soft Tonneau, Ford Bug Guard, K&N filter

Airaid pending

Future Mods:
a)Flowmaster
b)Superchip

"The Red Necksnapper"

 

Good-Guy Yes city driving burns alittle more gas than out on the highway think of all the starts and stops you do and well if you got a leadfoot like I do it gets even worse but its to much more fun to leave everyone else at the light.

 

I had a 40 series flowmaster installed about 3 weeks ago and dropped in a K&N filter the same day. I can tell you that I definitely got a performance boost. Which one had the greatest influence (probably the flownaster) I can't say for sure but it's a lot more fun to drive. My mileage has also taken a nice turn for the better.

****Next will be the superchip

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JJ
97 F150 Lariat 4x2 4.6l V8 Wht/Blue Flowmaster 40s Cat back system, K&N Filter, DeeZee Bugshield and Vent Visors