I've been wondering about this for some time. When I first got my truck I was averaging 18 mpg with mixed driving (60-70% Highway and 30-40 city) now that I am 20,000 miles in my mpg has dropped to about 15 give or take .5 mpg either direction. Has anyone else experienced this?

 

Winter fuel?

 

I don't think so because I bought my truck in December of 2005, so it was winter when I got it and was getting 18 mpg during the winter. Is all fuel blended during the winter across the US? I hear a lot of people saying that winter gas is worse but I've never heard anyone say that down here. I just changed my fuel filter and air filter so if my mileage goes back up, I may have to change those two more frequently.

 

My fuel mileage has gotten worse over time too.

 

I wonder what the root of this is? Carbon buildup, clogged fuel injectors, or what?

 

Fords aren't known for their gas mileage, so I stopped trying to figure it out 100,000 miles ago! I know that gas mileage is ENTIRELY dependent on how fast I go. I can watch it on the edge. If I drive 55, I sometimes can get 18mpg. If I drive 65, I'll get 16mpg. If I drive 75, I'll get 14mpg. If I drive faster than 80 I get close to 10mpg. And I drive the EXACT same path every week.

Seems like I remember getting 400 miles to the tank on a regular basis. But now, I only get maybe 300-330. I should be thankful though..... 200,000 miles, and who knows how many engine hours, it's a wonder it even runs.

 

This is too easy- your foot.

People take it ULTRA easy on their engines early on, and as it breaks in they get more and more brave and curious. the MPG suffers because of it.

And besides, I believe these engines are more commonly referred to as "broken in" around 10k miles.

 

lol man im right behind you there, 184k on my 4.6, the mileage sucks, the power sucks... but the pile will fire up and run fine every day. although i got a plug who likes to misfire once in a while... stupid t-stat leak....

 

Man, WHAT do you know? My truck has 200,000 miles on it, and it's just now getting broke in!!!! Shut up before my truck hears you. That's what matters.

 

You know what really sucks? I don't drive very hard. I can count on one hand the amount of times that the gas pedal has met the floor. Typically I find that my city and highway mileage is about the same. I guess driving at 80 mph is just as bad as stop and go as far a mpg but better on wear and tear. I have the 3.55 rear end too. I would hate to see if I had 4.10 instead. Maybe if I get an edge programmer I would know what was really going on. I would prefer a xcal2 but as of right now it looks like I will get neither. I've got a baby on the way, and I don't think the wife would take to kindly to my purchase of either. I might have to sell off some things that I don't use like say my golf clubs, electric and acoustic guitar, or my gary fisher mountain bike, just to name a few.

 

Dam I wish i knew our engines didn't break in till about 10k, after about 1k miles I kinda considered her broken in and let the pedal meet the floor every now and then. Oil filter change might help your gas millage a tiny bit but not much... In my mind every little bit helps.

 

try disconnecting the battery and erase the computers adaptive driving settings and see what that gets you

 

I may try that. How long does the battery have to be disconnected?

 

Not long. A few minutes maybe... Say 5 to be safe.

 

bah... so much speculation. Modern engines have vertually no break in period. Familiarity is why your truck is getting worse milage. Your comfortable with it and you drive it like a friend now. That uses gas. I have 2300 miles on mine and keep looking at the MPG part of the cluster.... just give me a year... I will forget that and it will be driven like I like to feel. BTW... a clogged fuel filter will NOT make your milage worse. nor an oil filter. It is strictly peddel depresion and quality of fuel used. these are heavy trucks and not bought for fuel milage concerns.. to a point. I like seeing the 16 mpg I get back and forth to work... not like my focus that gets 30-35 on the same route... talk about culture shock!! One thing I noticed that seemed to help... at about 42 MPH the torque converter locks. So I get to that speed reasonably fast and then let off the gas so the converter locks... then slowly accelerate to the speed limit and I feel it helps with milage. I might be all washed up.. but it seems to help to lock the converter sooner than later.