I drove from Louisiana to Tenn. and back. I got between 18.5 - 20.1 MPG, depending on speed and mountain driving. I have an 04 Lariat Screw, 5.4 with a Tonneau...if that helps.

 

Where do you people drive and get away with 80+ speeds? Speed limit on all the freeways in NY is 65, most traffic flows at 72-73. Cops will nab you at about 78, and they're always in the spots you tend to speed up, bottom of hills, right at the 65-55 transition zones, without fail.

 

alot of mid-western states have a 75mph speed limit.

i get 17 mpg in my 04 f150 SCAB w/ the 5.4l. highway mileage varys from 19-22mpg.

 

In Michigan, the speed limits on the freeway are generally 70mph, but everyone does at least 75, with most doing 80-85mph. Arent as many cops, so traffic flows pretty well... except for all of the road work.

I get 21mpg on the freeway at 75mph, but I have a '98 2wd, so I guess that doesnt count...

 

It is well to recognize that I did not state that I did not state 20+ MPG average. Neither do I have a 4X4.
I stated 20MPG on one tank.
I filled up again today and got 20MPG. Highway driving again.
As a general rule, I get 17-19. I do not do much stop and go driving. It is mostly highway driving mixed with small towns.
I think one thing that is very necessary for us all to understand in these issues is that driving habits make a difference. I try to not get above 2,000RPM when getting up to speed. At 80MPH I am not too much above 2,000RPM. That seems to be the sweet spot for mileage. If I dropped back to 70-75 I would probably get a tad better mileage.
Another thing to remember is that vehicles are different. 20MPG is not rare. On the other hand, it is not everyone who will get that kind of mileage. Why? The nature of the game. For some reason, some do better than others.
I believe there are several factors that contribute to my mileage:
1 E-fans
2 UD pulleys. My water pump is not slowed down so much that it affects the temp. It went up 2 degrees. I worried about that, so I put in a 180* thermostat. Mike Troyer said that 2* difference could have been caused by practically anything. The alternator puts out 13 volts at idle. That is sufficient.
3 Driving habits, as I mentioned above
4 Consistent use of FP60 and running 93 octane
5 Tonneau
I wonder why it is that folks question good mileage when someone states that they get it, but never question it when someone says "I'm getting 10MPG, what's wrong?" They simply answer, "You have a big, heavy truck...." Yet, if you baby big, heavy trucks, you get better mileage.
My $1300 that I've invested in various mods to gain mileage have helped. I spend $600-800 a month in gas. Two times I've gotten 20MPG. Generally it's around 19. I'm glad I'm getting the return on my investment. Be glad for me

 

Sounds good.
Speed limits down here are 70.
I pass state police all of the time @ 80. @85, the fines go way up. They want the money from the big fines.
On the other hand, I plan to try to go a little slower due to the principle.....

 

A 180* Stat just means it opens sooner, but wont actually do anymore to help keep your truck cool. Sure it may take longer to get up to 210* if it opens at 180* but once the temp is up past 200* it wont do anything different then the stock one.

And yes ive seen 20mpg once, it was a trip from dallas to austin, about 70-73mph with a tall desk and a dresser in the bed, they acted like a bed cover canopy. It was probably about 85* that day.

But i typically see only 13-13.5 mpg city b.c thats all i ever drive. I get on the highway but its very short trips like under 5miles on the highway.

-Patrick

 

What you say is true to a great degree.
You can dictate to some degree the coolness of the engine, however, with the e-fan controllers and thermostat. I run 186-188 typically. Sitting at an idle in 95* temps gets it up to 196 after about an hour. I am comfortable with that.
My statements were simply to relate the fact that the UD pulleys do not necessarily cause a vehicle to run significantly hotter. If I ever change the thermostat I may go back to the 192* stock. Troyer says 210* is optimal running temp.
I think I would get 14-16 if I were to drive all city. I'm glad I don't. I like to think highway miles aren't as hard on a vehicle.

 

I get about 200 miles to a half a tank of gas and thats if I dont get throttle happy i would like to see my truck give me 400 to a tankfull. FYI 2005 F150 Screw 4x4 Roush supercharger 30 gal fuel tank I think.

 

Do any of you have larger than stock tires? If so did you reset the speedometer? Would larger tires without resetting the speedo affect odometer reading and how would that affect mpg figures? I've got a '97 Expy with Troyer tunes and on 91-performance I just got 10 mpg. 1/2 city, half highway.

 

thats great.. your gettin that... but i dont have a supercharger on mine.. im not gonna go to that much extreme to modify my engine...dont have the money nor time to mess with it..... and a 1999 that i have... only came out with a 25 gallon tank.. 2005 trucks came out with a 26 or 27 or 35.7 gallon capacity check your papers on tag that list the options if you bought it new and still have them got it http://www.edmunds.com/used/2005/for...775/specs.html

 

Yes, the speedo must be reset.
Regards

 

I can realistically see 20 MPG with a 2wd truck with highway driving, and under the right conditions. I also think, that the nature of internet posting has some people overstating their claims. Is that you?? Maybe not. But from my experience in over 15 years of owning full sized, 4X4 trucks, 13 to 16 MPG is gonna be about where they fall. I have done all sorts of mods, experiments with driving style, etc over the years, and I have found it all but impossible to get over 16-17 MPG with a full sized 4x4 truck. I will say that every single truck I have owned gets oversized tires and wheels within 3 months of ownership, so that will knock a mile or two off the average. Yes, I take into account the difference in tire sizes when computing my mileage.


I am expecting a delivery of some E-fans I purchased off of ebay in the next couple of days, and this will be my first time using aftermarket efans. I am hoping to get my 2001 4x4 (5.4) screw close to 15 MPG with this mod. Currently the only mods I have is a Maggie exhaust and K&N filter. I also run synthetic, which I feel can help a litte bit. Even with those mods, I have run two consecutive tanks and not once in either tank did I get the engine over 2000 RPM. The result?? 14.3 MPG on both tanks. My speedo is almost exact and I also have a GPS setup in vehicle to double check my miles driven, so I believe these are very accurate numbers. I am hoping that adding the Efans and dropping the clutch fan will get me at least one MPG gain. I'll update when I get the fans installed and have run a tank or two with them.

 

Recent trip down south I saw 19-20 mpg on the highway with loaded truck, A/C on (5.4l, 3.55 rears and 4x4). That was running Xcal2 on 93 performance mode. I average 17mpg in mix of town/backroads driving running 93 tune, drops to 16 with 87 tune. No tunes I average around 14 to 15.

 

I think there is a vast difference between a 4X4 and a 2 wheel drive when it comes to mileage. I have 3.55 gears. I assume that most 4X4s have a ratio that makes it much harder to get good mileage.
I think the Efans will help you.
I am convinced that FP60 helps fuel mileage enough to offset the expense of buying it. It also helps keep the valves, etc. clean.
You'll probably be pleased with the Efans even if you don't see the improvement in the mileage. The added cooling at idle helps....helps the AC, too.