Flat ground with no wind, at 65-70 mph, my screw can get 20 mpg according to my scan guage. Best I have gotten on a tank is 17.7, combined driving. (On a cool day, no A/C, and the bed cover on) Even my Dodge work truck with the 4.7 will get 18.5 if I do the speed limit. Can't do it in town, I enjoy the sound of the dual exhaust on my screw to much. Lucky to get 12 mpg on a normal day of driving with the screw. My 00 Expy with the 4.6 would get 19mpg cruising at 65. Since driving with the Scan Guage I have learned there are way to many variables to try to determine why one vehicle gets better fuel milage than another. I have watched my Scan Guage showing 15.5 mpg, drop to 10.0 on just passing one vehicle on a two lane. Tires make a big difference, as well as the use of the a/c. My trucks lose at least 1 mpg just for the A/C. More around town.

 

mileage claims are only valid after multiple fills; 10 or more. Depending on the slope of the drive, my F150 fills can vary by 2 gallons. There is no way to make any mileage claim on the basis of one fill. do the same thing back to back 10 times and then i'd believe it.

 

1997 5.4L 4X4, and I average about 12 on the highway. If I'm real real lucky,.......I may get 12.5 MPG and thats running around 63 MPH.

 

All i can say is welcome to earth. What kind of mileage did you get on your home planet????..

 

I let mine roll down the hills..and got over 30 mph this summer..

 

I drove mine into the grand canyon and got a whoppin 85.6 mpg just before the sudden stop at the bottom.

 

My truck's the same as yours, only it's an '01 with true duals, factory Goodyears and an air raid-type intake. Combined driving of 70 mph on the interstate plus lots of curvy, hilly two-laners will get me about 17.5. I've only seen 18 once. I find that speed makes all the difference. If I'm on the interstate all day with the cruise set to 75, the mpg will drop to 16+. Daily driving with some stoplights, curvy and hilly roads, on and off the gas a lot will usually yield mid 16's. I guess I can't complain.

BTW...Have you ever eaten at Catfish Charlies in Ellisville? Yum

MR

 

I believe it could be done. Why would he have reason to lie about it?

I have a 98 5.4 4x4 extended cab flareside with 3.55s and 17 inch wheels that always gets 17.5 mpg on the interstate trips driving 75. I have gotten over 19mpg on a level road doing 55 for 200 miles. City driving sucks though...13mpg.

The only things not stock on my truck are true duals with flowmaster 50 series mufflers and a drop in K&N filter, I have full synthetics in the entire driveline as well.

I've often wondered if the electric fans and a set of under drive pullys would increase the mileage any.

 

Ok, maybe he didn't lie but, are you going to deny that his feet stink?

 

Hey, I've got a Predator tuned 2000 4x4 with a 5.4 and the 3:55's and the timing advanced 2 degrees and 305/70R17 tires and at 70 m.p.h. I can get a marvelous 10 m.p.g. (That's the best I can do) City is around 8 m.p.g. or should I say G.P.M.= Gallons per mile. Anyway engineer or no engineer I bet it was 170 miles downhill both ways. I've seen engineer's wrong before when I worked for Sumitomo Advanced Friction Products of America and we had Quality issues with our Brake Pads. The "Engineers" swore that by the specific gravity tests that our mixers had to be adding in extra ingredients and intentionally sabotaging the pads.... boy were those guys wrong... turns out that the Japanese owners and the engineers never thought that the humidity in Middle Georgia might be a little different than that of Japan and that the mixture(s) for the pads would have to be adjusted accordingly. So to make a long story longer I CALL B.S. TOO!!! Or at the very least I say that you should do what the scientific method says and REPEAT THE FREAKING TEST SEVERAL MORE TIMES!!!

 

GaBoy,
Have you had your speedo recalibrated for the bigger tires?

 

[QUOTE=ksuroper]GaBoy,
Have you had your speedo recalibrated for the bigger tires?[/QUOTE

The Predator has a prompt that allows you to input your tire size so yes I have calibrated that. Plus even when I ran the 265/70R17's I wasn't getting but about 11-12 m.p.g.'s but I usually keep my foot in it a great deal since I only get to drive her on the weekends.

 

His numbers aren't too far off of mine. The 3v 5.4L in my Screw FX4 routinely gets 21 MPG at 55 MPH with the A/C on. At 75 MPH, it drops down to 19 MPG. (Stock engine, no stickin' mods)

If I drive like an idiot, sure, my truck boggs down to 14 MPG on the highway. Driving style and tires will quickly rob you of mileage on the highway.

 

[QUOTE=98lariat4x4]I believe it could be done. Why would he have reason to lie about it?QUOTE]

We're not saying that he's lying. We're saying that he's measuring wrong or there is something out of whack.

 

I've managed as high as 17.2 MPG pure city, but you wouldn't want to be behind me.

I haven't taken the machine on a long trip, but I imagine at least 20 MPG. Gotta love the S/C.