I am getting reallyhorrible gas mileage and it is getting worse by the tank.. it used to get 12-14 and i was ok with that... but now the last 2 tanks were 9.36 and this last one was 8.66Mpg Its horrible. I dont think that I drive any harder than the next person....HELP!!!


This is how many miles I got to the last tank!



This is what i filled up today...and It actually cut off at $100 before it was completely full!

 

It goes without saying that we need a LOT MORE INFO. Such as Engine size, miles, mods, maintenance history, what has been done to the truck before the mileage started dropping. At this point we will be just shooting darts. Also, any codes (cel) showing up ??

 

sorry, IDK what i was thinking. it is an 05 5.4l 88k miles 35x12.50x18 trail grapplers, flowmaster exhaust and k&n. it has had a edge evo for the last 6k miles but before that I do no know. it is now on a stock tune.

 

How about the Maint. history ? Plugs, COPs, filters ??. With the Edge..is the PCM adjusted for the tire size ??

 

19.5 mpg last tank 100% stock

 

The Sam's gas might be the issue, I've heard bad things about it.

 

Yea when my truck was bone stock i could get 19mpg now with the 35s its just horrible it seems like something just happened overnight, i mean 8.66 is horrible.. I got the truck with 78K miles on it so I have no idea on what has been done, since i have had it i have done a coupleoil changes and a tranny service.

 

Maybe you have a gas leak?

 

That is terrible. At 253 miles I have just a hair under half a tank still.

I'd start with changing the fuel filter. It's cheap and easy to do so if it hasn't been changed in 88k miles it's long over due anyways and needs changed. From what I've heard about Sam Club gas (no personal expierence) there's a lot of sulfur in it which could plug you fuel filter. That's just "hear say" though, I can't provide any proof to back it up.

Since you're at about 100,000 miles I'd do the plugs also. Mine were pretty well shot when I changed them; a few of them the electrode was about gone.

Try cleaning the throttle body and MAF also. Either of them can cause a drop in mileage if dirty. When I cleaned the TB and MAF on my '96 I picked up 1-2 mpg. On my 04 I cleaned the TB and MAF and didn't gain much if any mpg but the TB wasn't too awful dirty to begin with.

I'd start with those 3 things first. They're relatively cheap and easy to do. Well, if you do the plugs yourself it's cheap(er). Taking it to the dealer will cost ya.



Take it to an exhaust shop, you could have a plugged cat. You could look at the cats after a long drive and see if they're glowing red also.

 

i cleaned the maf and throttle body about 2 months ago, and the plastic tab on the fuel filter is broke off and i can only get the front side disconnected... any suggestions on getting that off and where i can get another plastic tab?

and h=I really don't have the time or space to properly do a plug change, has anyone had them changed and if so how much?

thanks again

 

Those 35's will make a big difference in mileage (down). Its a heavy tire and lots of rolling resistance. At least do what MTM has to suggest and try a different gas, top tier if possible in your area. With the mileage you have, there are many items contributing to the poor MPG...just starting them out one by one. The plugs will be the most challenging for you.

 

also another question, it has been well over 100 degrees pretty much all summer, i think we are somewhere around 50-60 days of over 100 degrees here in longview, tx would this have any affect on it?

 

Here is your clip.........http://www.clipsandfasteners.com/For...e_p/a21127.htm

 

Hows your neighbors gas mileage? On a more serious note it could maybe be an o2 thats gone

 

I get terrible mileage on Sam's gas too.

You have an 05 5.4 - you MIGHT be having the leaky injector issue!

https://www.f150online.com/forums/v8...ram-07m08.html