ok i got a 2000 f150 4x4 with the 5.4 with 169000 mi on it i change my oil every 3000 mils and i i have 33in tires on it and their new spark plugs and new gas filter and i have streight pips and i got better air flow and i only get 11.3 and12.3 gas milage thats bad got any tips for better

 

dump the lead outta your shoes haha. i got a 97 with old plugs, stock pipes and intake and a filter that needs replaced and i get 14-15

 

I presume you have recalculated the error introduced to the speedometer and odometer when the large diameter tires were installed. If not, then your actual mileage may be 10-15% better than it looks.

The best tip I have for improving fuel mileage is the same tip I got years ago when I outgrew my need-for-speed: A light foot on the go pedal.