Went to Great Falls (about 250miles east of me). Made it on half a tank! (have the 26 gal tank) Soo i got close 20mpg!!!! I got 18mpg going over too... coming back is when i got my best, and both ways i was cruising 50-70 over the pass and 85 in the 75mph interstate. truck handled great.

 

i'll be first to call BS.
did you fill up and record the gallons and divide it out?
or are you basing it on the 1/2 tank gauge and assumption of 13 gal ?
i think if you fill it up you'll be surprised that it takes 3/4 of the 26 gal tank to fill it.

i've gotten as high as 18 on flat road at 55mph in OD with big tires, corrected speedo, and ideal conditions.

 

Nope i used peen and paper and a calc to divide the first trip. and the last trip is guessing but, i went farther on less fuel coming back so its should be slightly higher if not the same. Had a tail wind the whole way there and back. Coming back was a lot of down hill. I coasted down the long mtn pass mostly.

 

with 265/75/16's and the 5.2 I can't even touch that kind of mileage. If you truely did get that kind of mileage which you claim, what do you have done to your truck to do this.

 

That's pretty good, my best so far is almost 16 mpg and that was on my drive from Washington to Vegas. The last 244 miles of the trip was mostly down hill and flat so it made from easy riding. Oh and that was done without the use of cruise control...haven't fixed it yet.

 

I have 245s on my truck and no engine mods of any kind. Unless my fuel gauge randomly failed then I got close to twenty coming back., I know for a fact I hit 17 going there. actually it was like 17.6 or something miles divided by gallons used.... Tank before that I was 12 or so. So Im guessing it was my 245s and 392 gears(remember i have a topper and bumper oh and 200lb of sand all as extra weight. So I wasnt super surprised by 17 but i was at the same time lol.

 

Best I have done was 15 on my trip from cali to TX 9" of lift, 35X12.50 BFG muds and a 360 mag I filled her up till she pissed then drove 100 and filled up again then calculated the amount on the refill to the 100 miles I drove, I think 15 is pretty damn good for my big *** truck ;-)

Shawn

 

Just filled up... Drove 272 miles on 14gal of fuel(88 oct). thats 19.42 mpg. The miles are odo and gps confirmed. Also mpg was all hand calculated.

 

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I'll post for greg.

NOT A CHANCE IN HELL.