Just bought a 14 FX4 screw with the 5.0. Been out of the Ford game awhile since I sold my 02 5.4 little over a year ago. Just wondering what mods everyone has gotten the best mpg gains out of.

 

probably #1 gain is driving style. figure out what gets you the best for your exact truck and have a baseline.
for mine w/ 3.73's the closer I get to 60mph the better off I am(17.5 mpg), but I had a loaner with 3.31's and it did better around 70(18.x).


from there properly inflated stock sized tires, increase the size of the lower air damn, block off the front bumper opening completely, keep extra weight out of the truck.
that's about as good as its going to get w/o getting into lots of $ for minimal return. some people report good improvements with 93 octane performance tunes, but that's almost $.50 more/gallon here vs 87.


best bang for the buck for me has been using e85 or 87. for example I can drive 300 miles and get 15.5 out of e85, 16.5 out of 87 or 17.5 from 93.(oddly enough that's how it worked out). That costs me $35 w/ e85, $36 with 87 and $42 with 93.

 

I haven't even taken delivery yet, hopefully today. It has 3.55's and I don't drive fast 60-70 mph. Was just wondering if an exhaust and CAI would help out at all

 

The only thing that I'd add to BlackHD06's list would be .....

• routinely and religiously perform scheduled maintence.
  .
• check you front-end suspension and steering components and insure proper wheel alignment.
  .
• (if possible) when selecting tires opt for Passenger rather than LightTruck.

 

Lighter P rated tires for sure. You could gain some performance and MPGs out of a tuner, but that's a $400+ purchase.

A lot of reviews for aftermarket CAIs out there claim no difference or very slight difference in MPGs.

 

Do 'em for the sound and/or cosmetics.

Do 'em for any other reason and you're wasting your $$$$$

And before anyone piles-on ... YES! a tune could make the exhaust/CAI more effectual, however, the price tag would be in the $1500 range (CAI+exhaust+tuner w/tunes). *@$2/gallon that's 750 gallons of gas @20MPG that's 15,000 miles.

• the existing air intake system is CAI.
• the existing air intake system is MORE than adequite to meet even mod'ed engine CFM requirements.
• the existing air intake system will not contaminate the MAF sensor with oil and/or an oil film.
• the existing exhaust system (resonator -AND- muffler) are straight-thru and have little flow resistance.

 

Drive the truck like you bought and own it rather than you stole it and you will get the best MPG you can. Follow the advise already given and you will be in good shape.

 

Well, even though the 10 ply tires I bought are heavier, going from a "P" rated tire inflated to 35 PSI to my Michelin LTX MS2's inflated to 52 (60 when I tow our TT) --- we gained 2 mpg. Less rolling resistance at the higher PSI, I guess.
But as others have said here, there is no way you are going to recover your costs on any mod you do with the idea of saving money with increased mpg. Your driving style (taking your foot off the gas and coasting up to red lights, for example) is going to make a massive difference (5 to 6 more) in your mpg more than any mod.

 

Mostly highway right? Tire Weight kills it in town, less issues on highway.

 

With sound, yes. With MPG no.
You already got CAI. Aftermarket CAI is more like HAI anyways.