my gas mileage in my '04 F-150 is on a constant down hill slope and I need to know if any one on here has any fixes for this problem, and no I do not hot dog the rpms speeding up and starting I keep it under 2000 rpms. when I bought the truck i was getting around 13.5 mpg and now I am getting 10.3 on a good day now I have had the ruck for almost a year and I can't figure out why this is happening.

 

You need to post what truck you have and what engine. Does it have modifications? Oversize tires? you should fill in your profile information so it appears on every post like mine does.How many miles on it? It may just need a tune up. Oversize tires will make the gas mileage appear to be much less.

 

what he said


by chance did you recently fill up with E-85 gas?


and when is the last time your fuel filter was changed?

 

When was the last time the MAF sensor was cleaned?

 

^^^^^^ tire air pressure, air filter

 

Engine size? Cab and bed? 2wd or 4wd? Wheel and tire combo? Gear ratio? Mileage on the truck? Recent preventative maintenance done?

 

Highway Mileage Or City? How are you checking?

 

Im having the same exact problem! 04 fx4, I drive it perfect and i literally had almost the same mileage as you before ( around 13.5) and I now get around 10 or so. I had a k&n drop in and i was told that the oil can mess with the MAF, so i replaced it with a paper filter and got some MAF cleaner and cleaned it really well. I guess well see how that goes! You should try that.

 

routine maintenance can do wonders!! depending on the milage, trans flush, coolant flush, plug change, air filter change, fuel filter change, O2 sensor change and gear oil change. my '04 just hit 113,000 miles. i did all this at 107,000 and milage went from 10-11mpg to 14-15 mpg. (i only broke one plug btw).

 

my bro,inlaw has a 2004 f150 70,000 miles i checked the milage 2 times on the highway 21.5 at 65-70 mph, he had ford change the plugs ,soon after his gas milage went to poo,,,,,,i mean really bad,here in kansas the gas companys can put in 15% ethonal & not advertise it ,i have 2008 f150 same same set up,,he has 17 tires i have 18 my gas milage is not as bad as his???????????????/,,,,,,,,,he will burn 1/2 tank 70,80 miles no leak