In the last few weeks my gas mileage has dropped about 2 mpg.
I have no codes set.
Tires are inflated properly.
Exhaust seems to be flowing good (can't tell if there is any restriction in the exhaust/cats).
No noticable loss of power.
No change in driving conditions or usage of accessories.
Nothing has changed and nothing seems to be wrong with truck yet mileage has dropped.

Beginning to wander if gas formula has changed or something.

Anyone else noticed a difference?

 

Just filled both of mine yesterday (97 - 4.6 & 07 - 5.4), I've kept track of mileage closely on the 07 for the last year and it's within .1 mpg of average. The 97 was right around what I'd expect with the wife driving that so I'd have to say no identifiable change in mileage.

 

These motors tend to drop quite a bit of gas mileage when used with the 10% ethanol stuff. Make sure your 'regular station' didn't change up gas mixtures on you. An easy way to test, try a different station with known 100% gasoline.

 

Unfortunatly every station around here has 10% ethanol. I have tried a couple of different stations and still the same. Maybe it is just the heat (Very hot in Alabama right now).

 

run a tank of premium through it and see if that helps.....

 

#1-It's summer,and HOT. You're certainly running the A/C,which will work harder in the high heat, resulting in lower economy.
#2-E10 fuel-This crap is terrible for fuel economy, and unfortunately is everywhere now.
JL

 

It may just be a combination of heat and E10 fuel. Just odd that it is such a significant drop. I went from getting 19/20 to & from work to 17/18. That is a good hit. Can't get more than 18.5 on the highway at 73 MPH right now either.

 

thomast, respectfully, I am in suspect of your 17/18 claim let alone 19/20 mpg.
99.9% of these stock trucks never approch that mileage.
Certianly if I run with an eye on my monitor display, I can get the mileage up to the 17 range but that is never an average of overall fuel mileage due to stop and go traffic included, that drops the average down.
The ETH. in the gas will drop your fuel mileage as well as high ambient temps will retard the ignition timing , then add the A/C load on top of that.
The PCM is looking full time at the intake air temperature as one major way is controls ignition timing and fuel injection levels.
The OX sensors look at the extra oxygen produced by conversion from the ETH in the gas and increase the amount of fuel just from that action alone because the sensors are calibrated for gas without additives..
So you have a number of things going on all at the same time.
Good luck.

 

I have done a lot of mods to this truck to get it there.
Headers, Superchips programmer in Mileage XS mode, K&N filter and intake mods, electric fans with a switch that I can cut them off once moving.
I do get this kind of mileage if I watch for redlights and coast if it is red ahead.
I have also found that if you go ahead and accelerate up to speed fairly quickly it helps too. Not full acceleration but a good 1/2 throttle instead of slowly accelerating for a longer period of time.

I found a station today that had no ethanol (Supposedly). Will see if that helps.

 

thomt, it was rather 'not nice' of you to 'not say' what you had done to the motor before asking such a question.
Good luck.

 

Not sure what difference that would make. The mods were done back last fall. How would these mods cause it to suddenly decrease mileage.

 

This is a shot in the dark, Thomas, but check for critter invasion under the hood, in the intake tube in the fender wall, in the exhaust, chewed wires. Something could've happened that hasn't thrown a code yet, or may not throw a code at all but hinder it just enuf to throw the mileage off......

 

Good idea. I will check today after work.

 

Did you ever find out the problem?

I am currently experiencing the same issue with my 2006 Escape.

 

Never did. I just decide that it must be the gas and the heat. Now that the mornings are getting warmer, I am getting what I used to get in the morning.