mrlullabye

I've had a 2004 4wd 5.4 Expedition for a few years and it has always gotten horrible mpg. I'm talking 10 unloaded and 9 pulling a 4k# trailer.


Previously I had a 2000 expedition with a 2wd 4.6 that I averaged 16mpg inunloaded and 14 pulling a trailer. The 2000 drove a lot smoother and seemed to roll easy, the 2004 you have to keep your foot on the gas just to get it to roll.


I have taken the truck to 3 mechanics and they all say it is fine. It really feels like the brakes are on the truck, it slows quickly on the interstate, doesn't want to roll on level ground in idling in gear.


I have noticed that at times 4wd feels like it is engaged, it is hard to describe, but especially when you are pulling a trailer if you turn sharp at low speed like coming off a stop sign you will get a little shudder almost feels like a hub is locking and unlocking.


I have tried a kn filter, and all of the normal maintenance/tire pressure. The only thing I know of I haven't done is to change the sparkplugs.


the truck has 210k miles on the dash. No trouble lights on the dash, no smoke, no studder, or observable miss.


Any ideas are greatly appreciated.