91 ford truck 4.9 motor gas mileage isnt getting good gas mileage?

[JamesN]

i did tune up last year the oil gets change i drive about 160 miles a day 20 of it is in town its a 5spd. i drive about 70-75miles a hour

[itsthewill]

4.9 liters are about the worst on gas than all other ford truck engines. I have a 96 f-150 with the same engine and I'm lucky to get 17 miles a gallon

[rotus]

I don't think they got really great mileage to begin with, but here are a few things you might look into.



Get a free flowing air filter like a K&N or Fram Air Hog.



Make sure your catalytic converter isn't clogged. If it is, or if you want to replace it, find one that is as free flowing as possible. Same with the muffler. You can probably find a used cat off a late model wrecked Corvette that will work fine for you. Have a muffler show weld it on for you.



Run skinnier tires and run about 35psi in them. This will decrease rolling resistance, but also decrease grip, so be careful.



Get a camper top. Dropping the tailgate won't get you any added economy, in fact, it may hurt it. I had a tonneu cover on my bed and that didn't help either. Your truck is old enough that you can probably find an older camper top for not much money on craigslist or even a junk yard.

[PMack]

That's a full sized truck with a big six. What are you getting, mid to upper teens? Since your mostly highway it seems, I would think you might get upper teens, but I wouldn't expect any more.



Keep the tire pressure correct, accelerate leisurely, things like that will help, but bottom line is that's a big truck, it's not going to get good mileage.



Good luck

[jerryk]

at that speed you open the secondary and you loose 1/3  per gal,so if you are worried about fuel you should slow  down or get a toyota trundra