First off Sams Gas even if it may not be the best isnt going to make you loose 8-10 mpg ,

Take the truck to a Exhaust shop and get them to check the Cats.

I have a 07 4.6 supercrew and so far im getting around 16-16.8 with mostly in town driving. (I usually get around 230 miles to a half a tank)

As others has stated change the fuel filter, clean the maf and throttle body..

 

I get terrible mileage on both Sam's and Casey's. Where are you located and what other brands are available? I don't think Pilot is that good either unless they are getting it from Conoco.

Ask them where they got the gas, and use it.

 

Mississippi,
and how can I have my o2 sensor tested so i just dont buy a new one for no reason.

and does anyone know the location of it and the fuel filters

are there any other items that can effect the gas mileage as well besides tire inflation natur of driving and purchase place of gas

 

I have a 07 4.6 supercrew and so far im getting around 16-16.8 with mostly in town driving. (I usually get around 230 miles to a half a tank)



Im pulling 14 MPG and going about 270-280 Miles before i gotta fill up. grant it i have the 5.4L but still.

 

The fuel filter is located on the driver's side frame rail near the middle of the cab. It's an easy replacement, I recommend WIX filters found at O'reillys. That being said, I would have an exhaust shop check your cats for blockage before looking at replacing the O2 sensors.

 

I have an 04 4.6 STX 2wd like yours and I get 17-18 mpg with 50/50 highway city driving and 19-20 highway only. My driving style is moderately aggressive and I can easily go 400 mi on a tankfull. There is something wrong (maybe multiple little things) if you're getting the mileage you're talking about.

 

CATS

 

1. You need to get your Catalytic converter checked.
2. You need to map a route using Google maps from your house to a destination exactly 10 miles away. Drive the route and see if your odometer reports the correct distance.
3. Your wife is a woman, What ever is wrong with the car is her fault.

 

Don't bet on it ..... I have been traveling and have been bitten by tanks of gas that suddenly dropped mileage to near 2/3 or 1/2 what it was on earlier tanks leading up to that stop and I have seen the good numbers come back as I gradually worked the crappy stuff out over the next few tanks.

Not throwing off on Sams gas, I've never used it .... just stating observations made over the last 42 years that I've been driving and buying gas.

I will put in a plug for BP with Invigorate .... and Exxon .... here locally.

 

will call around and see who can check my cat that I can trust.
As for the map-quest wouldn't be easier to just get the distance to my work that i would e driving tomorrow and follow the exact route. it would end up being 10 miles more like 4 but it the same principal right

 

Still haven't told us what other gas is available in your area, and whether you have asked the dealer what they put in it for their testing..........

 

 

A lot depends on how much time you spend idling the vehicle (at lights, etc). I can get 12-15 in town (also a 4.6, but 4x4) if I get most of the lights in my favor, 10-12 when they're not. My wife drives "differently" than me and thinks nothing of leaving the truck running. She gets about 7-8 mpg in town.