i have a 4.6L 97 f150, it has 104k on it, i was wondering what the gas mileage should be and if there is ANYTHING i can do to improve it. i dont want to have to sell my pride and joy.

 

Is it an auto or manual tranny. Start with a good tune-up with Motorcraft parts. Tire pressures at recommended pressures in the doorjam will help. Only use the vent/panel or floor setting on the climate control. It will not run the a/c compressor that way.

 

My two biggest improve ments in milage tonnu cover almost 2mpg keep it under 70mph k+n air filter, under drive pulleys, helped too, also have predator didn't help on gas but worth the extra exceloration.Mud tires can hurt too. 5.4 4x4 scab 3.55 with this latest ethonal in gas getting just under 18 mpg was 19+for a while started at 15mpg

 

it is an automatic transmission, i am only getting 10-11 mpg. i have a full size topper for my truck but it isnt on now. how much will the topper help?

 

At 100k think lx is right do the tune up first then look for things like dirty sensors, egrs and throttle bodies there a lot of post here on all these problems and how to deal with them
unless it is just that you are a lead foot these trucks can really down the gas with a heavy foot
Big tires and extra weight can also kill milage
10-11 is pretty poor save for the foot thing