K&N filter update
Junior User
Joined: Aug 2005
Posts: 80
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From: Central Massachusettes
I am getting 15.1 combind driving every tank full. I was gonna do a bunch of mods but now I don't know if I should spend the $ or save it for gas in the motor home (V10!!) or boat 125 gal tank I can suck up in a weekend. Scotty.
Senior User
Joined: Nov 2004
Posts: 447
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From: Florida
Originally Posted by wedge88
What the heck am I doing wrong. I have 2003 F-150FX4 with SuperCab 4.6L and I get 14-15MPG. I have dual Magnaflow exhaust, run synthetic oil and have K&N Air Filter. I stay away from jumping on the gas, not loaded down with too much in the bed, tires balanced and aligned. Everyone I am seeing in this thread is in the upper teens with the 5.4L.
Junior User
Joined: Apr 2005
Posts: 74
Likes: 0
How in the world can you run one tank through an engine and claim anything? The claim by one poster that mieage increased by 2mpg is laughable. The only way to determine a mileage difference would be to run on a closed course at the exact same temperature, speed, weight load, wind speed....need I go on?
Before you put your new air filter on I am sure you measured more than a 0.2 mpg difference between tanks and this is more than the supposed claims of 2% increase for the K&N air filter. At best, you would need to record mileage and fuel usage over a 3 month time period to filter out your results.
If you really want more mileage, drive slower, put more air in your tires and maybe remove your tailgate.
I have nothing against k&N filters. I had one on a Suburban and a Harley but the purpose of the install was for more power.
Before you put your new air filter on I am sure you measured more than a 0.2 mpg difference between tanks and this is more than the supposed claims of 2% increase for the K&N air filter. At best, you would need to record mileage and fuel usage over a 3 month time period to filter out your results.
If you really want more mileage, drive slower, put more air in your tires and maybe remove your tailgate.
I have nothing against k&N filters. I had one on a Suburban and a Harley but the purpose of the install was for more power.
Senior User
Joined: Feb 2003
Posts: 155
Likes: 0
From: Edmonton, Alberta
Lighten up on the throttle. Start off easy and when you see the light is red let off on the gas don't race up to the lights and hit the brakes hard. I know it can be hard, but it makes a huge difference. Try it for a tank. You will be surprised.
Rick
Rick
Freshman User
Joined: Feb 2005
Posts: 44
Likes: 0
Running over 1000 miles in one trip on a freshly installed K&N FIPK I noted that I lost MPG. Not much, maybe .5 or so, but still. I do have the Flowmaster dual exhaust. Between the two, I've not gained one BIT of mpg. but it DOES sound nice 
Freshman User
Joined: Jun 2003
Posts: 37
Likes: 0
From: Ontario
Don't forget about reducing weight to increase fuel mileage. Anything you don't need to haul around take it out (sand bags from winter).
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Senior User
Joined: Nov 2004
Posts: 447
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From: Florida
It has something to do with the back draft and turbulence, when the tailgate is up, it creates an "air pocket" allowing the wind to flow over the bed somehow. I don't really understand it myself, but I seen it on a tv show, trucks! maybe? or may have been mythbusters, not sure.
Junior User
Joined: Apr 2005
Posts: 74
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Junior User
Joined: Aug 2005
Posts: 78
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From: Northern MN
I got a 1-1.5 mpg improvement with a soft tonneau cover on my 02. In town driving you don't notice much of a difference, but on the highway you sure do. A hard tonneau will give you better mileage results than a soft cover, but I like the soft one because I can roll it up to haul larger items if need be.
Senior User
Joined: Feb 2003
Posts: 155
Likes: 0
From: Edmonton, Alberta
I recently bought a roll-n-lock box cover for my 98 5.4l 3.55 AO4D. I made a trip from Edmonton to Grande Prairie, Alberta and back 1100km total. I got 21 mpg both there and back traveling at 108 kph (70mph). The mileage is about 2 or 3 high than any before. I keep track of all my fuel that I put in my truck and my over all average is around 14.5 mpg (Canadian gallons)
Rick
Rick