'04 Lariat Screw 4x4 w/5.4L and 2750 miles. 360 mile highway trip - - Got 14 mpg on flat land and 80F outstide. Cruised at 60-70 mph.

Normal everyday driving to/from work 16 miles per day gets me 12.2 mpg. 50/50 city/highway. Keep it below 2500 rpm and the mileage improves to about 13.4, but the fun factor goes way down. Nothing but 87 octane $ince new. Hopefully, this will improve as things break in.

I suppose if you had no wind, no hill, accelerated like an old lady, always coasted to a stop, set the cruise control for anything over 35 mph, and the weather was 77F at 29.92"Hg with 50% RH, you might be able to achieve sticker mpg.

 

I'll believe it when I see it....

Your computer must be lying!

 

I don't have a computer. STX 4.6 3.73. I've got 2800 miles and I keep a running average of my mileage on every tank. I've tried real easy acceleration and driving under 60 for a tankful and tried regular accel and 75 mph back and forth to work and every tank is about the same. Within .5 mpg or each other so far.


Believe it or not. There's a lot of guys on here claiming a lot more than I'm getting (18-20)

 

It is just difficult to believe that I have the 4x2 (lighter) 5.4 3.73, and I am only getting 12.2 MAX on the highway. 12.3 if I put tailgate down with bed extender.

Wish I knew what was going on. Avg HWY Speed 65.

What is your Idle set at? Mine is around 500 RPM.

Thanks,

Dave

 

A little higher than that..maybe 600 or so.


I think that with these trucks there is a HUGE variation of performance and economy. There are people reporting 18-20 mpg and people reporting 12 mpg. Some have the 5.4 and report better mileage than a lot of the 4.6 guys (like me) I dunno why, but that's what I'm hearing....I really expect to get better mileage once I get around 6K or so on the truck

 

I have a 04 S/cab with 5.4; 3:55 gears and average 16.5 mpg. 18 mpg hi-way. I don't waste any time when I'm driving. I get 12 mph when towing my Jeep on a 14 ft. open carhauler, about 4500lbs. total.

 

My 04 Lariat Scab w/3.55 LS and TruXedo bed cap now has over 17K miles on it.

Since tuning with a Superchips programmer, my regular mileage jumped from 12.5 to 16 MPG, at 75-80 MPH. Towing an enclosed trailer with a total weight of 6,000 lbs, mileage at 65 MPH is 10.2 MPG. Plenty of power for me with the Towing program, with no other engine changes.

I like this truck.

Bob

 

Just made an 1800 mi run from TX up to MT mostly around 70-75 on cruise, air mostly off w/the 3.7 gears and averaged around 17.5 (calculated) High of 19.5 and low of 12.2 on tank basis. Got to agree however this is a "flat-land" outfit, when you hit the hills, especially at higher altitudes, the throttle goes wide open and usually downshifts even on moderate grades. Don't know where the torque curve peaks, but must be a lot higher than the 2k rpm this thing shows at 70, 'cause it acts like its way off the curve most of the time. Also I think this thing must have the aerodynamics of a brick, if you'r running into any kind of headwind the mileage drops off fast. Running into a 30 mph head wind across Wyo it was downshifting on level ground to maintain 70 and the mileage on that tank went to about 12. Can't complain too much however, the '03 screw I traded wouldn't get 12 downhill with a tailwind. Got about 6k on it now, and have run several tanks of all three grades of gas thru it and see absoutely no difference between regular and higher octane, if fact I think it got a bit worse mileage with premium. Like someone else said, could be due to the slower burn rate. I do notice a significant drop in mileage on the ethanol blend they sell up in this country (about 10%) probably due to the lower available btu's per gallon of the ethenol which also seems to cause a fairly rough idle. On the whole, I can live with 17 hwy/15 city I'm getting it's a lot better than my old '03 and a helluva lot better than the Dodges and most of the chevy's I'v owned, let's face it we'v got a 3 ton block of iron to push thru the wind and carry a load, it's no Honda Civic and was never intended to be (Thank God!)

 

My standard cab 5.4 with 3.73 gets 14-15 around town and 18-19 on the highway here in the mountains. The best fuel saving device is attached to your ankle.

 

My Lariat F150 (2WD) 5.4 Liter, short bed with bed cover gets 17.0 mpg in town and 20.0 mpg on the highway. On the highway I do 70-75 mph (1800-1900 rpm). Use 87 octane name brand gas...usually Bp gas. No trick stuff installed on engine....

Dave

 

Thanks for the clear and concise summary, Bob1044. Your experiance mirrors mine. I'm starting to call this my 'Kansas' truck... Cause it needs flat land..



Osbornk, your right about the best gas saving device being on your ankle. The second best for me is a vaccum gauge on the dash. It reminds me to 'adjust' the first device...

Oh well, this is still the most fun to drive truck I've ever had.
Chris

 

I have about 14k miles on my 04 SCrew Lariat 4x4... no mods - just a bedcover. When doing all highway driving I usually get between 16-17 MPG - in town I average between 12-13. When towing snowmobilies on the highway I was down to the 12-13 range.

 

If you think about it a minute, we're comparing apples and oranges. When you consider the different styles and diffeent gear ratios, you should expect a wide variation in fuel mileage. My "little" short bed standard cab 4X4 weighs hundreds of pounds less than a Screw. My little truck weighs just over 5,000 pounds and many others weigh nearly 6,000. It's almost like comparing the mileage of an empty truck and a loaded truck. It's no wonder the Screws do poorly in the mountains.

 

I have a 04 Screw FX4 with 3.73 and it has ~2700 mile on it and the best I have seen is 14.9 twice and this was on an 800 mile trip with 90% interstate driving. In town and interstate it likes to stay around 13.

 

Osbornk, you may have a point. It does seem that the Screws get worse mileage than the others.. I can't find the curb weight stated anywhere of these vehicles.