Hello everyone! I need help! Does anyone have any inexpensive ideas on how to improve gas mileage for 2004 F-150's with the 5.4 L? I've had my truck since March '05. I have installed a toneau cover and that gave me 1 mpg, but I keep seeing these air intake things I can install and wasn't sure about buying it because it's rather expensive. Do you have any ideas or suggestions? Or any testimonials to the air intake systems? Preferrable something that won't void the warranty. Thanks a bunch!

 

...Welcome to Ford Truck Enthusiasts! Please read the Guidelines, it will help you to navigate through and understand this site.
Stick around someone will be by shortly to answer your question.
We are happy you have chosen the best source for Fords!

Enjoy FTE....and
JOIN CLUB FTE -SUPPORT THE FORUMS!
…..See you on the boards.

 

welcome to FTE I have a 04 larait screw with the 5.4 and 373 ls . when you say better mileage what are your baselines that you are working with so we can kinda get a idea if there are any improvements to be had of if you should just smile when your at the pump . my truck averages about 16.5 to 18.5 with mixed city and highway driving. have had it up over 20 mpg with cruise set on 70 and all the windows up that was resetting the gas mileage indicator when i got on the interstate. of course the more active you are with your left foot will affect your mileage. some tips try to keep the RPMS under 2000 and easy accleration .My mods to my truck are flowmaster 40 series muffler with si/do and 4in chrome tips, K&N replacement airfilter, and AIRAID replacment airintake tube and also had the omputer reflashed at the dealership to make sure it had the latest update from ford.

 

I improved my mileage from 15.2 to 16.4 city MPG by installing an Airaid tube (not with the Airaid filter, kept stock filter and looking to add Wix disposable for more air flow) and a Magnaflow muffler. Total cost was $90 for the tube and around $160 for the muffler. Engine runs like it was made to do so. Smooth and strong, yet better MPG.

 

Toreador...two things.

1.) Can I get some info on that tube swap?
2.) You need to make a gallery! I just tried to see said swap, and it said there was no gallery .

 

A big improvement an come from your driving style. Avoid jackrabbit starts, use the cruise control, and avoid using a/c or rolling the windows all the way down if you can, and drive between 55 and 65 on the freeway. Also, keep your tires properly inflated.

 

There have been a lot of threads written about this lately and one of them mentioned the use of a product called a Scan Gauge. (Scan Gauge.com) I tried it and love it. Installation is simple, plugs right into the computer plug under the dash. Have increased my highway by 4.5 and city by 2 mpg. I think it actually makes driving more interesting as well. My only complaint is that the letters and numbers on the screen could be a little larger. To my surprise I found that I can do better without the cruise on. Welcome and enjoy the site its great.

 

Guys what am I doing wrong? I always hear poeple throwing out #'s like 16mpg and 18 mpg and I just don't see it. Granted all my driving is city traffic (have a company car only use the truck for pleasure) but the best I have ever gotten was 14 and change. I've got a 5.4 screw. I have a friend with the same truck with a 4.6 and he claims he gets about 19-20 running to nags head. I find this extremely hard to believe.
A little help here please!!!

 

gpeade: I like you found it hard to believe that the numbers could change but they do with a little change in your driving habits. Chris Adams wrote a nice thread not too long ago about this and his explanations were very easy to understand. By just backing off the gas a little bit when going down a hill can make a big difference. You may want to do a search for Chris's article. (best I can say it was about three weeks ago) He was to one who mentioned the Scan Gauge. It gives a read out every two seconds on a variety operating conditions, one of them the actual estimated mpg's and you can see them change in accordance with your foot's movement on the gas pedal.. I might also add that 60 mph is best speed for economy. Hope this helps a little..

 

Well, anything between 55 and 65 will balance freeway travel with economy, but on other roads, your actual best mileage speed can vary. My Dad's '00 V6 all wheel drive Passat's best economy speed was 42mph, at which he got 48mpg! My Mom's '04 Sienna AWD likes it at 48mph, at which she gets 34-36mpg. Anything above that best economy speed, and you start to lose mileage. But, back to Bobri's point, 60mph on the freeway should yield you about a couple mpg more than doing 65.

 

I HAD A 2002 WITH THE 4.6 with a fiberglass cap and averaged almost 20 mpg on a trip at 65mph.My 2004 5.4 with 373 rear also has a fiberglass cap and on a trip at 68 mph I can average almost 19mpg.

 

I have a 05' XL HD payload 5.4. I get 15 mpg whether I'm towing or not, hwy or city. The sticker said 15- city/ 19- hwy. I'm guessing the 4.10 rear has something to do with it. Towing a camper behind it- you don't even know it's there.

 

I can believe that. The cruise control on our trucks holds the speed so constant that it hurts the mileage when going up hills. I tried a little something a few months ago while on a trip from Greenville to Atlanta on I-85. I held the throttle almost fixed, going 80-85 down hills and slowing to 65-70 at the crest of the hills and my mpg on the info center read 20.5 mpg when I got to Atlanta! It was reading over 21 until I got into heavier traffic towards Atl and had to stop varying the speed so much. The same trip with the cruise set at 78 gets about 18.5 mpg.

 

You noticed that too. Yeah, it's the most 'tight' cruise I have ever seen, even on cars costing far more.
Down side, is you hit a grade, and it will keep you at EXACTLY 70 or whatever. I have the habit of whenever I hear it pitch up, I tap the brake and go 'manual' till I'm up the hill, then resume. Works OK, and I have the habit from my Motorhome, which will roar up a hill like a banshee if you don't release it on hills.
Chris