Migz

okay guys I have a 08 f150 4.6 bought it a year ago never did a tune up ran great from the start but I do notice that when ever I park it while it is running maybe for 5min -10mins max. The Gas just goes down amazingly fast I mean I have stayed stunned at the amount!!! Any salutions or is it just the way it's suppose to be?

2008__XL

Have you actually calculated the miles divided by gallons on multiple tanks in a row? If not, then you should do that to see how much you're actually using.

Are you parking on an incline?

And what do you mean the gas goes down? Are you leaking fuel or are you speaking of the gauge?

Migz

No i mean the guage bro it horrible if I'm in the car on my break turn it on with the A/c on I'll be in there 5-10mins max just checking my phone and the marker will be right before half tank mark and after it will be Moving less than half a tank. I have noticed after I drive it around it will try to get back to where it was but a noticeable difference

Summers22

iTrader: (2)

So have you or have you not hand calculated mpg's for the last few tanks?

blupupher

iTrader: (2)

A fuel gauge is a very inaccurate device.
It is not to be used to calculate mileage or fuel consumption.
You need numbers, specifically number of miles driven divided by # gallons of gas used to fill it full (if it was filled full the last time) over multiple tanks to get an accurate number.

You say it moves down while idling, but then moves back when you drive?
No way to figure out usage while idling unless you fill it full, let it idle for 10 minutes, then fill it again.

Jojodapyro

While idling you get zero miles to the gallon. That is an easy one to figure.

techrep

iTrader: (1)

and while idling with the A/C going you get -0 MPG...

650NutKase

Bad float in the tank? IDK, I agree with others here. Calculate the mpg's per tank. You may be possibly sitting on an incline, making the gauge read less than what you have.

scobar

iTrader: (4)

There is no data to support the claim the truck is using excessive fuel.
As many have mentioned you need to have some real, hard data to back it up. I would not rely on the the trip computer/DTE to calculate any MPG or as a diagnostic tool.

What you can do is fill your truck up until the gas pump clicks. Stop here, you are full. Write down odo reading.
Now, do whatever you do that makes you think it is using fuel. Write down after odo reading.
Top off to click and subtract. This is how many miles your truck used with whatever the amount of fuel you just put in here. Hint: look at your gas pump/receipt for the gallons. If you did not drive, then use the number of minutes or hours, etc.

If you want to continue with this topic I would suggest:
Show us total miles per tank with total capacity (mpg)
Show us evidence of this excessive fuel consumption
Share what if any maintenance or troubleshooting has been done (people here will suggest what to do but YOU need to do it and report back). Things like plugs, tune up, filters, etc. This is important.
What grade of fuel are you running and where do you live would also be helpful.

blupupher

iTrader: (2)

True, but I did say usage, not MPG.

But if they drive 200 miles and use 20 gallons of fuel with no idling, that is 10 MPG. If they then filled up, drove another 200 miles (similar to the previous) as well as idled for an hour during that time and used 25 gallons of fuel, that is 8MPG, with the idling for 1 hour useing ~5 gallons of fuel. No idea if that is a little or a lot though.