I have a 98 f150, 4.6L, with almost 80,000 miles on it. This weekend a friend and I took his chevy huntin', and he was getting about 350 miles per tank of gas. his engine is bigger than mine, but the gas tanks are the same size. in my truck I only get about 230 miles per tank. should I get more mileage than this? I am thinking about taking it in for a tune up, or doing it myself, but overall it runs good, havn't had any real big problems with it. any suggestions?

 

Probably time for new cap, rotor, plugs, wires, cleaned air filter, cleaned throttle body. That should help you get better mileage.

 

Did you recalibrate your speedo after putting on the larger tires or did you compensate for them when figuring out your MPG? If not, you are getting more miles per tank than you think.

 

even before i put my tires on i was getting low milage, maybe around 250 i think. i did add a little extra for the bigger wheels though, even though i don't think it changed very much. i guess i might just change all that and see what happens, any other suggestions let me know. thanks yall. any suggestions on some side step bars? thats what i am working on right now.

 

I have 97 SCAB 4.6L A/T 2wd that I have 80,000 miles on. I've done nothing but routine maintenance. I average 16 mpg in the city (Phoenix), and 18 mpg on trips driving 70 mph. Pulling my bassboat drops my mileage by about 2mpg. I think you have a problem.

 

That don't sound right. I have a 97 with the 4.6 extened cab 3rd door. 140k mile allways ran 280 to 290miles per tank per tank, interesting note i put in a k and n air filter and the last two tanks gave me 340 mile. But not to sure yet as both tanks were used on very long road trips.

 

TAMU is that the gas mileage your truck has always got or is it getting worse?

 

Racerguy- when i bought my truck a year ago, it had stock tires and was getting about 250 miles per tank, now that i put on my new tires i get about 230 with the low fuel light on. why so much gas? about a month or 2 ago i had my oil changed, they showed me my fuel filter, it was the original one that was on it when it was first sold, even that dirty, weighed about 1/2 pound. i guess the guy i bought it from didn't take good care of it. what should i do?

 

A tune up would probably be a good idea. New plugs, air filter if it needs it and clean the MAF.
You might want to replace the thermostat too in case the engine isnt getting as hot as it should be which can cause low gas mileage too.

 

I have a 1998 F150 XLT Supercab 4x2 with the 4.6 and 140,000 kms (86,991 miles).

On a tank I get roughly 500kms (310 miles) considering it's been nearly -50c (-58F) here, winter gas, and I have about 200 pounds in the back for extra weight.

 

TAMUO, have you calculated MPG yet? (by dividing miles by # of gallons you add). This might help clear things up. If you are getting under 13 MPG, something is wrong. You said you got 250 miles per tank before. That in itself is horrible mileage.

Do what Racerguy and the others suggested then calculate MPG and let us know if there is an improvement.

 

Now I'm thinking something's wrong with my truck, too. I only get 14-15mpg in a 2003!

 

According to my calculations, I'm getting roughly 13 mpg average driving.

 

I just filled up this a.m. I got 18.21 mpg with the 5.4. That is if my math is correct, same as Cperry's formula. (389.9 miles divided by 21.4 gallons = 18.21 mpg). I slowed down a lot in the past couple months and it made a huge difference. I used to run 75mph to and from work. It only saved me a few minutes so I backed it down to 65. What a difference! I was getting about 16 mpg. I know it's only 2 miles better, but it makes a difference on the wallet in the long run. I do mostly highway driving, no mods, stock tires, and a soft tonneau cover. I am expecting a drop when I throw the 235/75R16's away and go to the 285/75R16's. Just wondering if you're a leadfoot? I know it's tough sometimes with that power available not to run it hard all the time.

 

Three fillups on my 5.4. and I've seen no better than 15mpg. I drive 70 miles daily on the highway - about 15 miles in traffic, and routinely drive 70mph with no traffic.

I just put on a Bullet cat back exhaust so we'll see if I get some improvement - maybe will add Airaid intake too.