I never really paid much attention to my MPG until now when gas prices are going through the roof. I have a 03 f250 4x4 5.4 with 3.73 LS with normal size tires. I did the math and I am only getting about 8 MPG. I am not an agressive driver and keep my foot of the gas as much as possible and most of my driving is hiway. This MPG number seems really low. I have about 56000 miles on the vehicle and I am not sure if the fuel filter ever has been changed since I am not the original owner. I replaced the air filter but this did not help. Can you give me some suggestions or let me know if these MPG numbers are average?

 

well keep the air filter clean, make sure you use the right oil which is 5w20 for your truck, make sure the tires are inflated to the right pressure.

 

Tryin changin out your fuel filter, clean air filter like ford390, keep your foot out of it (toughest obstacle to overcome), Try avoiding complete stops if you can, and when it's safe of course... it takes a lot of muscle to get something that heavy rolling again from a dead stop... I try my best to keep it between 40 and 50mph whenever possible as that's what I've found to be most economical... Obviously you can't do 40 on the highway and 50 in a school zone. just common sense stuff - anything you can think of that will save a little here or there, it all adds up in the end.
When I first got my truck with 39k on it, I was getting 12-13... Then I started doing these simple things and I've had I'd say the last 8 or so tanks calculating out to 15 or 15.5.

Good luck

 

I also try to keep the RPM's under 2k when ever possible (including taking off). Just by doing that I have increased my mpg by at least 1.5 mpg. It might be a little slow on the start, but like Cuda444 said "Those little things add up".

 

When I can I try to keep it under 2K, it is slow but I am surprised by how many cars I still keep up with

 

8mpg??? That is way, way too low. My guess is that you have something wrong, more than just aggressive driving. My truck is like yours, '01 4x4 5.4 3.73, and the lowest I ever get is around 11, and that is when pulling a 16' flatbed trailer with a 3000lb tractor on it.

 

best thing for gas milage i did is put on a summit racing muffler. summit brand was 25 bucks then had it put on. haven't check the fuel milage becasue i'm not throught he full tank yet but as of right now i'm getting ready to hit the half mark have 195 miles on the tank so far!


what does everyone else get to the tank or before the fuel light comes on with a 29 gallon tank AND A 5.4?


my light has been going on at about 300 miles and i still have 4-5 gallons in it based on the refill amount.

 

Haha, I almost crapped my pants when you said 195 to a half tank and I assumed you had the same tank as me, 38 gal. I hit about 260 at half a tank and get 15-15.5 mpg. I just got home from work so I'm too lazy to do the math to compare our mileage based on your info, but off the top of my head... it sounds about average.

Mike makes a good point by saying that 8mpg is way too low. You may want to check to make sure:

1. Your hubs aren't engaged
2. No calipers are sticking

 

2005 Crewcab 5.4 3.73. 300 to 310 miles, 4 gal, or so left when the light comes on on a 29 gal. tank, also. Last tank was 14 mpg, highway, avg. 75 mph. My 99 supercab, 5.4, 4.10 got 12 to 15 mpg depending on driving speed, conditions, etc.

 

I replaced the fuel filter this afternoon, hopefully that should help some. It was the original motorcraft filter on the truck. How do I check to see if the hubs are disengaging or if my calipers are sticking?

 

If a caliper is sticking, the rim will most likely be covered in brake dust and/or noticably warm. When mine stuck, after driving 10 miles, you could feel the heat with your hand from about a foot away... The rim gets hot to the touch. You could also jack the truck up and make sure the wheels spin freely. If you have manual hubs, it should have "FREE" and "LOCKED" written right on them. If you have the automatic... Try putting in 4x4, drive around the block, drop it back into 4x2 and back up a few feet. The other way, jack up the front and turn one wheel by hand, if the front axle turns with the wheel, the hub is engaged.

These two things are just things that popped into my head. Hubs because they decrease mileage substantially if engaged, and the caliper because I've been there.

I'd say start by jacking the truck up one end at a time and make sure everything turns freely and that the hubs aren't engaged

Let us know how you make out

 

hey another suggestion run some injecter cleaner through that thing and make sure you use 2 of them or dont fill up all the way because at most they treat like 20 gal

do a tuneup on it also if you havnt allready, if your plugs are all used up, dirty, not gapped right, stuff like that can kill fuel miles ecspecially in a big boy like these

 

2003 super cab 5.4 3.73 285/75/16 10.5 city 9 highway with 5300# trailer 75 mph

 

That is about right for me too. I absolutely hate the truck I bought. It is slow, lacks any sort of power and gets horrible mileage. I resorted to using my 1989 Bronco II to tow my 12' flatbed trailer because it takes off better from a stop and uses about 30 gallons a mile less in fuel. I will never EVER recommend a 5.4L to anyone!

I am on the lookout for a PSD. Just sucks I have had this truck less than 3 months and wish I would have never bought it.

 

the 285/75/16 didn,t help power or milage. thinking of putung in 4.30 gears to help towng, not that concerned about milage not my daily driver.