Gas milage issues.

[BAgee87]

I've done A LOT of research on this and done all of the simple stuff and even fixed some other things that should help once I figure the root of the problem out.

I'm getting 10ish MPG. The engine runs and sounds perfectly fine. I just purchased the truck from a buddy and he said he NEVER got below 14MPG and that was a worst case scenario.

When was enquiring about the vehicle the transfer case motor was bad and the 4x4 control module would mess up frequently. He replaced those got it going and then I bought it. Since then I have replaced the spark plugs, gave it a oil change with seafoam treatment in both the gas and oil. I also noticed the truck wasn't heating up properly and changed the thermostat out on it and that all is going great but hasn't helped with the milage issue. I'm at a loss. There are no check engine lights or anything and it seems to run fine. Could the issues it had with the four wheel drive have something to do with it like its not disengaging properly or does it stem from something else?

Any help, Tips, or trouble shooting info would be great! Thanks in advance.

 

[roamer37]

The real fix is warmer weather, with my experience as a engine calibrator at ford motor to make a engine start cold you have to richen the mixture at colder ACT and ECT temps this is using much more fuel during warm up and even normal driving. Air is much Denser at cold ambient which requires more fuel to run at 14 to 1. Our old methods with carb's did not take that into the equation so cars run much better but we get decreased fuel economy.

 

[gamikzone]

yeah winter does have a negative effect on mileage, ive been using e85 ethanol lately and after around 170 miles im down to 1/4 from full

 

[05dakotatrac]

1. E85 will always net a 25-30% loss in MPG. 2. your mileage doesn't account for the minutes untraveled warming it up 3. when your car is cold started it runs up the rpms and shoves more fuel in till it warms up this also consumes more fuel.

 

[BAgee87]

But is 9-10 MPG really common for cold weather? We've had spurts of warm weather to and it still didn't help. Everything I've read says I should get around 16. I have a mustang with a 4.6 V8 and my old man has a 97 F150 4x4 with the 4.6 as well and neither have suffered this badly from the colder weather.

 

[Markaprice73]

No, I don't think it's that common. But, being a new driver of this brick you have to change you driving habits for sure. 4 mpg difference between you and your buddy tells a lot right there. Check your tires air pressure. (I usually run 1 psi over the recommend psi on the door jam sticker) I just aired up my fathers 07 ST (it was 5psi low) and he's instantly gained 2 mpg's. Idling kills mpg's. Keep your foot "out of it". My Wife gets 13mpg when she drives my ST. I get 19. (ScanGaugeII would be a great purchase)

Great info roamer and dakota!

 

[Markaprice73]

Have you check this? PCV elbow. I ducted tape that sucker in the middle of a road trip across country years ago. I swear my mpg's went up 1mpg at least. ? It won't always throw a code. Mine didnt.
http://www.explorerforum.com/forums/showthread.php?t=314670