My new best is now 24mpg on the dot, up from 21mpg. I drove 4 hours on the highway yesterday with the cruise set @ 55mph. I'm running 265's inflated to 60lbs. I'm using EFI live to shut off the EGR (doubt that had much if any impact at all), and I'm running Timing Table C, which is advanced injection timing for high altitude. I think this is what made the big difference in conjuction with the slow driving. The advanced timing is basically free cylinder pressure. I covered 192 miles empty/no bed cover with 8 gallons even.

There are no changes at all to the fueling tables. I did this with the stock LLY 310HP/605TQ tune. I know there are a lot of nay-sayers about high fuel mileage with these trucks, but those are real numbers I posted. It's amazing how much slowing down a little and 2 minutes of tuning can do.

awesome numbers! pm sent

Congrats! Man, that is awesome.

Impressive mileage. I recently went from Phoenix to San Diego w/ my truck. Only upgrade I have the Edge Attitude and Juice. I intentionally drove at 65 MPH on cruise control to see what kind of mileage I could get. The best I could muster up was just under 20 M.P.G.. Of course I had the wife and kids along. I tell you what, I'll never do that again. Couldn't get to San Diego fast enough....

Nice Mileage!! I'd kill for those kind of numbers.

My '04.5 is totally stock and I can't get better than 16.3 doing that same 65mph. Been from Seattle to Phoenix 2 times and it's the same both times. First time I had a bed full (everything fit under the bedcover), and the second time it was just the bed cover on it.

I gotta find some inexpensive way to up the mileage!!!

Terry B.

Best fuel economy I have ever gotten was when I was coming back from school on the 9th. I was goin 65 and got 21.2 MPG that was good for me. I have 285's and a bullydog triple dog- it was set on performance when that happened(Most likely due to the lack of wind on the drive... a rarity in South Dakota)

Nice Mileage!! I'd kill for those kind of numbers.

My '04.5 is totally stock and I can't get better than 16.3 doing that same 65mph. Been from Seattle to Phoenix 2 times and it's the same both times. First time I had a bed full (everything fit under the bedcover), and the second time it was just the bed cover on it.

I gotta find some inexpensive way to up the mileage!!!

Terry B.

get EFI Live i get 19-20 mpg driving around the city. i am gonna go up to Michigan from NC next month and thats just around 900 miles. last time i did it i only got 16ish mpg but that was stock. so im hoping for some good numbers.

get EFI Live i get 19-20 mpg driving around the city. i am gonna go up to Michigan from NC next month and thats just around 900 miles. last time i did it i only got 16ish mpg but that was stock. so im hoping for some good numbers.


Can you please send me the program you are running on EFI Live? That is insane mileage. I'm sending you a PM with my email.

And i thought i was doing good. The best i got was 18.5 on the highway cruising at 70, wearing 265's and the air pressure pretty well maxed out. But then again i am running my race tune.

Can you please send me the program you are running on EFI Live? That is insane mileage. I'm sending you a PM with my email.

pm sent.

yea i just filled up and hand calculated i got 19.5 MPG 398 miles out of the tank.

It must be certain trucks do better or it is a lucky combination. I travel from SC to Chicago (975 miles) every month and get 19.8 to 20.2 every time. The mileage goes to the lower side dependent upon traffic. 2-5 miles an hour over the posted limit. The truck is stock except for a K&N air filter. I have Michelin LTX's in the stock size with 55PSI all the way around. Bed is loaded @ 700 lbs or so and the mileage does not change when empty.

I keep the truck serviced pretty well. I do notice that when the boss drives it, the mileage goes down to 18 but he is very heavy footed during acceleration. I guess he's used to having to hammer his F-150 to get it moving.:D I am always reminding him that with diesels, a little goes a long way, but what can I say he owns the truck and pays the fuel bill. I don't have too much ground to stand on.

I got 24 once on a test run with cruise set at 55. But once I knew I could do it I couldn't keep the speed at 55, I fall asleep. So now I just work on trying to keep it at around 65 or 2000 rpm. Still hard to stay awake though. :D

I believe that timing has a big part in mileage. I run my Predator on 120 and I see the best mileage there, probably because the timing is advanced a fair bit on that setting. This just confirms what I previously thought.

Timing is definately important for mileage as well as opening the vanes on the VVT. I've seen as high as 25mpg on the freeway at 60mph on flat a surface with the tune I'm running but I have to go through town to get on and off the freeway so my average mileage is between 19 and 20mpg. Yes these mileage numbers were taken with the DIC but it's accurate to .2gal per fillup.

slt223 thank you for sharing that, and Congrats!

I would say A TON of free torque is left on the table with factory tunes. I want to bump my timing up a little more with stock fueling tables, and see where it goes. FWIW, I tried doing this about 5 months ago but stopped, because advanced timing made my motor sound like a pound of bolts in a washing machine on spin cycle. Advanced timing and cold weather/cold motor don't seem to go together to well.

Nice...

I just put on some 235/85's last weekend, Monday I drove from Savannah to N C on I-95, set at 1950 RPM @ 67 MPH I got 21 MPG. And I did reset the tire size with my tuner, odometer is dead on, so its accurate...

I was wondering today what I would get doing 1500 RPM @ 55 ish...

Buy the way What does it all mean?

Mileage sounds like what I get. I travel the highway to work at about 55mph and also get 24mpg. I average around 21-22mpg with all the city and highway driving I do. Glad to hear someone else is getting that kind of mileage.:rockit:

I have super chip Flashpaq set at 90 horses and 4 inch turbo back mrbp exhaust and pulling 28 foot horse trailer with three horses and gear got 16.1 for economy.

This is running 265 tires