milage off

[STANGM89]

i know this isnt about a cobra but my other vehicle i went from 16 ince wheels to 17 inch and on a tank of gas im losing about 75 to 100 miles could the bigger wheels make the speed odometer be off that much?it seems like she can go just as many days as she could before its just the milesage is differant
thanks billy by the way its a 2002 expedition 2 wd

 

[missouri_guy197]

Did you plus size the tires? If your overall tire/wheel height stayed the same you shouldn't have any issues...What's the size of the old tires and what's the size of the new tires?

 

[STANGM89]

Did you plus size the tires? If your overall tire/wheel height stayed the same you shouldn't have any issues...What's the size of the old tires and what's the size of the new tires?

it may not be my tires i had to have2 coils replaced at the ford dealership so they talked me into a computer upgrade on the expedition she said it would improve my gas milage and shift better since then my gas milage has went from 19 to 14 i called back she said what they done wouldnt hurt my milage and said my fuel filter could be bad.is this possible? i thought a bad fuel filter would cause it to run rough.thanks