I bought a nice 98 f150 with the 4.6l and 285/70/17 tires as well as true duals...and the first full tank it averaged 10.8mpg I've searched and I can't find anyone else doing that bad..

.I thought ok I did some hammering and city driving but yesterday it burnt a quarter tank in 40-50 miles I forgot to reset the trip odometer so I can't check the mileage on this tank but the 40-50mile trip was all highway...14-15 with the big tires would be fine...

air filter is dirty and will be changed today...exhaust still has o2 sensor...gonna change plugs too...maybe run some fuel injector cleaner through and do the gotts mod....any other ideas?

 

Nope. You're doing fine. Quit complaining.
I do worse than you with stock tires. I know others do as well.

Here is what you can do:

Clean:
MAF
IAC
EGR
Throttle body
Motorvac engine

Replace:
Fuel filter
Air filter
Tires - nonaggressive
Synthetic oil
Front diff synthetic oil
Rear diff synthetic oil
Plugs
Cops/Wires
O2 sensors

Check:
Tire pressure
Alignment
Brake drag
Gas cap seal
Your driving style
Your weight
Cats - unclogged
Vac leaks
Gas tank staps for leaks
Extra weight, remove unneeded items in

Buy:
Efans
Eco tune for programmer
Different gears depending on where you drive and your tire size

 

x2
Is it a 2wd or 4wd?

 

4x4

 

Everybody likes to add a few miles onto their calculations, that's why. It's the middle of winter, I'm happy with my 10.5 mpg.(315/75/16's, auto 4.6, 4x4). It'll go back to 12-13 soon enough. Winter gas, using the heat, icy roads and snow all have quite a bit to do with your fuel mileage along with the cold weather and a few other little things.

 

If your in a northern region where they have winter blend fuel that's about right. Wait until summer and see what you get. Most of us are getting around the same with winter blend. I have a 02 screw with a 5.4 with 285s and getting 11 mpg at best right now, get close to 14 I'm the summer.

 

His weight tackle, really! Hahaha I know a few hundred pounds can make a diff, I just think its funny you through that in there. Funny, not surprised.

 

Do you have this stores somewhere that you copy and paste it? Haha I have barely seen 8 at its best point all winter with a 5.4. And 33's I got 2 at one point earlier this year. You bought a truck man! It's to be expected, if you wanted milage sell it and buy a car.

 

No. I understand how to run the Search function and can find my old posts where I pasted it.

 

Hahaha!