i have noticed the gas mileage in my 05 3.7l 2wd has been awful lately. i use to average 17 in town and 21 on interstate. as of late i get 14 town and 16 interstate. the better mileage was with all the extras cai, flow master, plus one size mud tires. i am close to the 60k service on my truck but i just cant think of why the drastic change. i know the ethanol they are putting in gas now effects the mileage as a friend of mine that has an f150 says he has seen about the same drop. i was wondering if anyone else has noticed the same thing and if they have found a way to help get it back up. also i run synthetic blend 5w30 and full synthetic in the rear end. anyone have any ideas or help?

 

I have noticed the same thing in my 06 4.7 dakota. I thought it was because my hubs are pretty much shot. Maybe its not that

 

What are your gears/cruise RPMs? I average about 21 or so HMPG but I'm also 2 wheel drive.

 

If it makes you feel any better I only got 12.5 mpg out of my last tank. Pretty painful

 

I always see a slight drop in the winter months with vehicles i've owned. I check my mileage every fill up. Since I've had my truck, got it in July, I've averaged 17.5 mpg mixed driving. That was in the summer months and early fall. Since about Nov. i've only been able to get 15.5 mpg. I chalk it up to idling more since it's cold out, and I think they put some kind of additive in the gas here in CO. in the winter? Everyone I talk to gets 1 to 2 mpg less in the winter around here.

 

acording to the sticker in the glover box it has 3.55 gear and the 4 speed auto. i know in the winter months the change the gas and you get worse mileage but i have noticed the drop in the summer months also. i have a 2" kit on the front and a trans cooler just to help in the heat down here in the south. just for reference my stock tire size is 245/70/16 and i have 245/75/16 maxis buckshots on now.

 

i have noticed the drop also every winter, but it is due to the crap they put in the gas to stop it from freezing, one thing i did notice was low tire pressure, i run 40 psi an the mileage got better. might want to check the pressure, the door jam says 35 psi, tire max is 44 psi, i run 40 to be safe

 

My mileage has been down about 1-2mpg lately too. Only since about Jan 1st here though. Although...idk why there should even be a 'winter' blend here in Phoenix!

 

I am with ya all... my mileage has been down a tad, but mostly because it sits and idles for about 10 minutes on avg and with the useless fuel, its understandable. I am happy with it I don't know about you guys, but with the SC Tunes, the truck loves to eat fuel when idling, more so than stock... atleast the overhead displays this. I have checked it by hand a few times and its with in a few tenths.