I've run most of my vehicles on Synthetic oil and never had a problem. I think it's the way to go. I also heard that an eletric fan could get you an MPG, anyone have any data to support that?

I have the 2004 5.4 and wondered if anyone makes an OEM looking/fitting electric fan replacement for my truck?

 

Brand new screw, 3.73, 4x4 and same exact issue. Mine is exactly 2mph off. Wierd is that it is 2mph off at 55, 60 or 70.. really does not matter on speed.

 

I have gotten 19.7 once
Trying for 20 now.

 

Just got back from trip down Rte 15 and Rte 81 from NY to southern border of Virginia, 4 people in the truck and A/C on. 50% hills, 50% straightaways. Averaged around 70-75 mph. Average MPG was 19.1 on super unleaded

2003 F150 STX/XLT 4x4 with 5.4l and Xcal2 (Thanks TP). usually average around 16 around town. (and I have my foot into it alot...)

 

well currently i am getting 5~7 MPG. (i need new o2 sensors)

when i use sunoco 93 + octane booster i get 10mpg

 

I just got done babying my truck seeing just what kind of mileage I can get. Check this - not ONCE in 200 miles did I get the tach over 2K. Not once. I mean I babied this thing. I also used my GPS to get completely accurate miles driven assessment. And I could still only get 14.3 MPG. It was about 60% city, 40% highway miles, but still, I can't even get my truck to crack 15 MPG. I'm not sure what kind of mice you guys who are claiming to be getting 17 to 21 MPG have under your hoods - but they must be on steroids, cuz mine suck compared to yours.

 

Try doing ALL highway miles...it will be MUCH better. Same rules apply though...nothing about 2000 RPMs.

 

2003 Supercrew 5.4 4x2:

13-14 around town
16-17 Highway

1998 F150 Supercab 4.6 4x4:

11-12 in town
17 Highway

I don't see how anyone can get 19-20 mpg with these trucks. ITS A TRUCK.

If ya want good gas mileage... you bought the WRONG vehicle.

 

I am getting 14mpg on my 06 XLT super crew 2 wheel drive with 5.4 and I drive mostly highway. I have a factory tow package and 285/50r20 tires/rims. Do you do anything to get to the 19mpg?

 

Kept a record of our fuel consumption for a trip to Florida- 1506 mile from Canada
The trip south - 16.6 mi/ us gal - 14.81 liters / 100 km.
The trip North - 16.56 mi / us gal

Truck was 2001 S-crew liariat - 5.4 / with K&N air filter. From the stories I've seen adding the K&N FIPK wont pick up any more economy.

Just Purchased a new 2006 S-crew FX4 with 5.4, 20 inch wheels, 3:55 axle. It will be interesting to see if the fuel numbers change , but I doubt they will. I will post new photos If I ever stops raining in eastern Ontario.

 

2002 XLT Supercab, 5.4, 4x4, 17" wheels, 3.55 LSD

10 mpg towing
12 mpg city
14 mpg highway

The gas around here is 10% ethanol all the time.

 

I like your optimism, but I seriously doubt I would get much better than 15 to 16 MPG tops, even with all highway miles. I have been driving full size trucks for the past 12 years and none of them got better than 15 to 16 highway. Most were still well under 15 MPG. In fact, my last truck (Chevy Avalanche) got the best overall mileage of the bunch at about 14 MPG for the 37,000 miles that I drove it. This Screw ford I have now seems a little bit more thirsty than my Avalanche. I have been contemplating buying some Efans to help with the mileage, but I'm not sure the $300 + price tag is worth it. Plus I don't feel like spending 5+ hours installing them. If I could have gotten in on the $220 group buy from Juneses I would have sprang for them though.

 

All highway miles keeping it under 2000 RPMS should get you 16 mpg. I get 15mpg doing about 75.