I have 143K on my truck. I did the TB, MAF, IAC cleaning last year this time. That was when I saw my best HIGHWAY mileage of a whopping 14.9 mpgs!! o2's are another thing I'm considering. I've read where some jump a few mpgs with new o2's. Replace the Fronts--correct? ......not the rears?

Yea, I was guessing my tires even though they are stock size are heavier than a stock tire as they are LT tires 8 ply! I really like the BFG ATs, but probably won't put them back on when I replace them. They were on the truck when I bought it and were fairly new. I still have A LOT of life left in them so it won't be any time soon. I was thinking of possibly going with Bridgestone Duellers when that time comes.


Another reason I'm pissed about my mileage is I drive it SOOOOO conservatively! I mean I don't stay in the lower gears when getting up to speed as I try to get through them as quick as I can using the least amount of RPMs possible to get into that overdrive gear. And I coast so much. I look ahead and see the light is changing, so foot completely off the gas.....where a lot of time I don't even have to hit my brakes as the light has turned green and traffic is moving again. I have that imaginary egg under the pedal.

ALL of this and I can't get decent mileage!!---DirtySCREW

 

What maintenance have you done?

 

Never mind had the tab open and you responded before I did :o

 

Maintence----new MC plugs last year.....maybe has 5-7K miles on them, TB cleaned last year, MAF cleaned last year, new fuel filter last year, new brakes all the way around when I bought the truck, replaced wheel bearings & seals this year---DirtySCREW

 

try replacing the forward 02s

 

MC or Bosch? I think I remember that the MCs were suppose to be better even though OEMs were bosch. Am I correct?---DirtySCREW

 

I know my mpg's drop when going over 65 mph.. To date, I average 15 mpgs commuting to work and back. It's 18 miles each way, with about 14 of those miles on the hwy.. But, that also includes traffic and the city driving..

On straight hwy runs, I can get an honest 16-17 mpg's if I keep it under 65. I got the 17 while keeping it at 60 mph for over 200 miles.

I've got over 215,000 miles with the stock O2's, plugs with a zillion miles on them and I've never cleaned the TB or the MAF. I've been towing the TT in my sig for over 8 summers now and only run Shell or Chevron Regular gas. I've not had a CEL since my IAC went out on me about 6 years ago. I do all the other regular maintenance stuff with the fluids and keep an eye on everything else.. Call me lucky I guess, but I'm satisfied with the performance and economy of this truck..

I do have 3.55 gears and larger then stock tires, but I did recal the speedo, so it is as close as it can get..

Remember, each time you hit the brakes and press the gas, you are getting worse mileage.. Driving habits make a huge difference in mileage, especially in traffic or city driving. I know you said you had a 99% hwy run and only got sub 15 mpgs, but I can drop my mpgs down to single digits if I want to!

Good luck with it.. I'd try a run where you drop your speed some and try to be 'hyper' sensitive on how you apply the brakes and the gas... Try letting off the gas when you know you are going to have to slow down ahead and coast up to traffic.. Don't try to keep on the bumper of the car in front of you so no one can 'cut' in on you.. You do have to give something to get something, so that's just part of the game..

Mitch

 

I got the best mileage with my hypertech back in the day....

 

I get the same results as Mitch150 discribes.
02 super crew 4.6/3.55.
I have a monitor and if I try hard to keep the instant miles as high as possible, I can get it over 17 mpg on a run.
Otherwise general driving average is about 14.5.
Differances will ocurr with changes in temperature and how much extra load is aboard.
Even a full tank of gas will result in less mileage until it goes down to 1/4. A full tank is about 150 lbs of weight.
So there are a lot of vairables at any given time.

 

can anyone answer why im only getting 11 mpg's on average with my 01 5.4 4x4 with 3.55LS .....??

hould i be getting more or is 11 about right??

 

I only read the first page but there has to be something wrong here. My 5.4 with 35's going over the rocky mountains in cruise control (with construction and 30 zones) netted me 19.2 MPG.

City I get FAR worse (12/14) but straight cruise I can almost hit 20 with my truck. All I have is an edge as well.


Also I am 4x4 with 3.73 LS



Edit: maybe because I am an '07? I am just surprised it would be that much of a difference.

 

^^ you also have an 07 with the 3 valve engine. all of us have 2 valve 03 and lower year models...

hince why this is in the 97-03 forums...

 

you should be getting atleast 15mpg. Maybe try your front o2 sensors clean your maf and keep the right foot light. If you will keep the rpm's at or under 2,000 you should see better MPG's

 

Anyone? Bosch o2s or Motorcraft o2s????

Cosworth--that is excellent mileage considering you have 35s. I just want to make sure you are taking your MILES and dividing the gallons of fuel it took to get your truck back to full (starting with a full tank of course). If you are doing that---BRAVO!!! You da man. But like others have said, you have the 3 valve and we have the 2 valve. That does make a difference. Also, do 07s have e-fans?? That again would make a big difference.

My next step is replacing my O2s as they have 143K on the (factory original). I'll clean my TB and MAF as well when I install the o2s---so the combination of all three SHOULD net me my desired results of over 15 MPG highway.

I can't describe how conservatively I drive. I basicly hypermile for those that are familiar with the term. I should be getting better mileage. I just think somethings not right. I don't want to throw money at it, so I'm trying to take the educated approach.
Plugs are good--replaced last year--only have about 7K on them
Tires are constantly monitored for air pressure---mine are at 50PSI (again I have the BFG ATs and that is their MAX pressure--trying to have the least amount of rolling resistance possible)
I have a K&N cone on Airforce 1 intake and Magnaflow SIDO to help with air in & out
Differentials have Royal Purple synthetic gear oil in them
Bearings & seals were replaced this year---that DID reduce some parasitic drag I had and gave me about .4-.5 better MPG!!!
Motor oil is MC syn blend and changed every 5K miles with new MC filter
Fuel filter was changed last year

The ONLY thing left is:
Changed Trans fluid and transfer case fluid to Synthetic (I'll be going with Amsoil)
E-fans!!!!!!!!!!!!!!!!!!!!!!!!!!
New front O2s!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Maybe try some Denso Iridium plugs
and maybe a programmer--Edge/gryphon

If I do the above four, I should get 19-20 on the highway! Again, I'm in Eastern NC....no hills! Flatland!

Ahhh--this is frustrating....especially when people have lift kits, 35s and I know they don't drive as conservatively as me get a lot better mileage!!

I'll gladly accept donations for a 2011 F150 Lariat FX4 with the 5.0 Coyote motor!!!! LOL---------------DirtySCREW

 

I did mention that and as I mentioned I am surprised it is THAT different.




Yeah I am just shocked 1 valve makes it THAT much more efficient. '07 doesnt have e-fans