Greetings!
I have a 1997 F350 4x4 SRW Regular Cab with the Fuel Injected 460/Auto. The truck just turned 80K and i really don`t drive it much. I use it to haul firewood and take a log to the sawmill once and awhile. Most of the time it is in low range. Here is the problem..I am helping my neighbor put a new roof on her Mothers house which is about 50 miles round trip with mostly interstate driving. I have dual tanks and when they need filled i just drive the truck to work and fill them. So on Friday we leave to start the roof and by the time we get there i notice i am at the 3/4 mark and didn`t think much about it as i though i must have used more fuel the weekend before cutting wood! I am use to feeding 460`s and know what to expect! My truck is well cared for and is not driven in the winter and sits in a heated garage so we are not talking about a beater rust bucket! That would be my 83 F250 with 460 auto 2wd that gets 9/10 mpg highway! The only changes that i have done to the truck this spring were to put all new ball joints,disc brake pads and a alignment. Plus i replaced the tires with a new set BFG`s that are the same size as what was there!

So why is my truck consuming so much fuel? Last summer i checked the MPG and was getting 10.5 on the interstate which was a 125 mile trip one way and i checked both ways! I am going to try check for codes as i read about doing that. The truck is running ok. The 4x4 is disengaged. The engine is warming up to temp quickly. Something has malfunctioned!
Regards
Gene

 

If your truck has dual tanks, check to make sure that fuel is not being transferred to the tank that is not in use. This is a relatively common problem.

Another thing to check is for dragging brakes. If a truck is rarely used it is possible to have a caliper stick. These trucks have so much torque that you would not notice the problem right away.

The most common high fuel comsumption possibility is associated with our right feet...

Lou Braun

 

Thanks Lou! I will drive the truck and check for a overly warm wheel!But i didn`t notice any pulling. I went out and checked the gas gauge and i am just below the 1/4 mark and have 96 miles on the trip odometer. Yes i understand the right foot problem and i do tend to exercise my foot regularly!!! But these trips have been at 65 nph and using the cruise with only about 3-4 miles of highway driving and no in town putzin! I started out with 2 full tanks and decided to watch and verify with the trip the mileage. Both tanks went too quickly! I am aware of one tank feeding the other through the tank switch. I will check the other tank to make sure that is still almost empty.I know one should not ASSUME ! Plus i am hauling a ladder and a couple of tools! No heavy weight. Every thing was delivered to the house.
Thanks
Gene

 

You might try to get the codes read and see if anything is giving codes.