I purchased a 2004 f-150 with 5.4l in June of 2009. When i bought the truck I was averaging about 21-22 MPG's on the highway and 14 in-city MPG's. I am now averaging 16-17 MPG's on the highway and 12-14 MPG's in-city. I have not done any modifications to the engine or drivetrain since my purchase. The only things I have done since purchase is upgrade the stereo system (in-dash navigation, new door speakers, two amplifiers, and a stiffening capacitor) and clean and oil my K&N air filter.

The only things I've read or heard about is that the audio system can interfere with the ECM causing a loss in fuel economy. Also i noticed that my loss in fuel economy came right around winter. I was also told that there is a winter blend fuel that may cause loss in MPG's. Is it possible that I over oiled my K&N filter, causing less effeciency?

Any ideas?

 

yes there is a winter blend & yes it lowers your mpg.. but im told the winter blend should stop in may at some point... the intake does absolutely nothing for you but put more dirt in your engine & look better

 

If you over oiled the K&N you could have contaminated the MAF. Clean it. Not a big deal and it could improve your performance.

 

fuel.

 

When does winter blend end? Anyone know?

 

K&N claims their recharge oil does not foul the MAF. Do I believe them? I don't know.

*Don't shoot the messenger*

 

fuel filter, clean TB and maf

 

That might be true on the newer models, but I'll never trust an oiled element again.

If it's over oiled, the inside of the intake gets tacky and you may find foreign matter stuck to it.

The dry element Amsoil nanofiber filter is a drop in and very easy to maintain, without worry. A step up from the factory element. I believe their cheaper than the K&N as well.

 

^ alot..looked at a amsoil for mine i think it was 38 dollars..almost 3 years ago when i bought the k&n for my truck it was about 68 or so

 

Fram has a washable air filter for less than $25, that is good for up to 150,000 miles. I can't see paying $18 apiece for filters, and I sure as heck don't want the hassle of one of those oily pain in the butt things like I have on my lawnmower.

 

I've never had the oil problem you speak of on any oiled filter I've ran on any vehicle I've owned. Seems like you're speaking of a user error issue more than a problem with oiled filters.

 

my truck came with a kn filter when i purchased it. i never noticed any over oiling like that either but i do alot of driving on gravel roads and the kn filter is worthless if you drive through dusty conditions. i was shocked by the dust that could pass through that thing.

 

There are warning about dusty conditions and the K&N: 'K&N Air Filters should be cleaned every 50,000 miles for normal highway use, more often in dusty conditions'. For an aftermarket K&N intake they sell these filter covers that aid in dusty condition filtration.

 

Well I did keep it clean and oiled but the dust seemed to pass through. This was within days of cleaning and oiling it. This was with a stock intake (Gotts mod only) and past the filter the plastic intake interior was lined in dust. Ever since I've replaced it with the Amsoil filter the dust hasn't reappeared

 

That's good, nanofilter.