SuperNac

Just did my 30,000 mile oil change and replaced the air, cabin air, and fuel filters as well. Thanks to these forums for the fuel filter swap !!!!!!

Just ran out my 1st full tank from after the change and my MPG dropped from an avg of 21.5 down to 18.2. I've checked for leaks around the fuel filter and the plastic cover panel feels dry. If there were a small fuel leak would it evaporate between the time I shut the car off and immediatly get under it to feel around for the leak?

My filters were extremly dirty, brown gas came out of the old fuel filter. But I'd think that I'd see a raise in MPG if it were performing more efficiently.

Any suggestions?

mpatilla

How are you checking MPG? The old fashioned way or do you have the computer? If it is with computer, there might be a miscalculation because of the loss of fuel during the process of changing the filter.

On a side note, how much did it cost to replace all of those filters? I am about to hit 30,000 myself.

SuperNac

I check the old fashioned way. My 06 doesn't have the message center, and from my experiances with our old Mountaineer I never trusted the MPG computer anyway.

I think I spent around 120.00 for the filters and oil.

5 quarts Quaker State 5w-30 full synthetic
K&N Oil Filter
K&N drop in Air Filter
Purolator Cabin Filter
Can't remember off the top of my head on the fuel filter it was like 12.00

Ford Dealer Quoted 415.00 for the 30,000 mi maintenance.

mpatilla

Was it your first tank of gas after the filter changes where you calculated 18.2? Could there have been any other factors, like different driving conditions? I have calculated everything from 18 - 30 so I wonder sometimes if there is an inconsistency in the fuel shutoff.

mpatilla

So did you replace all of the filters yourself? Was the fuel filter hard to get to?

harlanb1

I have a 2001 Ford F150 pickup.
On the last tune up, the technician (who i trust) said that the fuel filter was about 50% plugged and was limiting
how much fuel was getting through. He said that the gas miliage would probably go down with the new filter.
And it did. thatmay be the same thing that is happening with you.

mpatilla

Did it go down and stay down? Or did everything equalize with time?

SuperNac

Thanks for the info harlanb1.

The old fuel filter seemed pretty dirty ala the brown gas that came out of it when I poured it out. I guess I'd just assume that if the fuel filter was plugged the car would have ran like poop and when I changed it out and made it more efficient the MPG would have gone up. I'll keep monitoring before I freak.

Mpatilla - this post was made after only my 1st real full tank of gas after the filter change. I'll keep monitoring. I had 1/2 a tank when I changed out the filter spilled some gas and still got 20 MPG on that tank.

Lethaldosage423

MPATILLA: Heres how to replace the fuel filter...pretty easy stuff all you really need is a small set of basic tools and a jack/stands or ramps.

https://mustangforums.com/m_3713378/tm.htm

red07Pony

Kind of like rebooting your home computer.... Did you take your negative battery cable off and leave it sit for a couple of mins and then hook it back up?