Anyone Else Disappointed In Mileage?

[Robertc82]

I want to start this off by saying....No I did not buy this truck to get great fuel mileage. But I did trade a 2010 6.4l with way more horsepower on 37's with a 6" lift that got every bit as good if not better mileage than this truck. I was just under the assumption that everyone was getting 17-20 mpg. I am still breaking mine in and expect it to get a little better but 13 mpg...come on. I was really hoping to see 15 on every tank. I drive really good, never over 70...60-65 a lot...and this is all empty. As far as towing, I know it's going to suck no matter what, so that is not an issue. My speedo is 2 mph off so it's pretty close. All mileage is hand calculated. Lie-O-Meter has been consitently .5 mpg off. I have the XRT pro and have tried all three settings with pretty much the same results. I didn't buy it to get better mileage either. I have thought about deleting, but from what I read, it doesn't make enough difference to even do it, so I am leaving mine together as long as I can. I guess I am just writing this to tell my experience. I absolutely love my truck and wouldn't trade it for anything, I just expected a little better. Any one else disappointed?

[dhanna6powerstroke]

I have a few friends with 6.7's and they all see 17-18+ mpg and their trucks have 3500 miles or less.

[stroke11]

It always could be better, what did your truck get with the stock tires. I found that speed and head or cross wind kill mileage. With everything perfect I got 18.8 with the cruise set at 74 on a 400 mile hwy trip. Our trucks are so different to compare though. I also have 331 gears.

[Nthorseman]

The big wheels look pretty and they put the truck up in the air more...that's probably where a lot of your gas mileage is going.

[Robertc82]

Really I didn't see any difference with the stock tires. I saw 13-14 on average.

[gary2070]

Maybe regear???

[stroke11]

Im guessing your 6.4 was tuned and deleted. Also with your speedo off your not getting a correct reading its not 2mph across the board its more of a percentage.

[Robertc82]

Originally Posted by stroke11

Im guessing your 6.4 was tuned and deleted. Also with your speedo off your not getting a correct reading its not 2mph across the board its more of a percentage.

Yes I was running the 300 tune with Spartan. I am tuned with this truck as well, just not deleted. I realize that my speedo being off is not giving me the correct mileage driven, but it is only off by 2 mph by gps at 70 mph. It was 2 mph off the other way stock. So i don't see this being much of a difference.

As far as regearing, I don't believe this would help. I am running 36" tall tires with 3:73's vs the stock 32's or whatever. These trucks come with the option of a 3:31 so I figure if anything the taller tires should help in raising my gear ratio. The tires and wheels are definitely heavy, weighing about 170 lbs a piece I think, and that hurts me, but raising my gear ratio balanced it out I think.

I don't believe there is anything wrong with my truck. I was just expecting a little better mileage out of it. I don't think 15 mpg is an unreasonable number. And I am not starting this rant to gripe and wine, but just to hear others opinions on what they are getting and if they too were disappointed or very happy with their mileage. Thanks guys.

[jflow730]

I take my little boy to work with me on jobs and let him watch videos while letting the truck idle. Sometimes it sits 2 hrs at a time and combining that with city driving I am getting 14.5-15.9 mpg's hand calculated. It has improved slightly since it turned passed 10k miles.

On a recent trip I got 19mpg going to Dallas but "only" got 17.8 on way back due to stronger head wind. Truck is stock and 3.55 gears.

[PUMPED 101]

I get 16.5 with winter blend, 3.55 srw, only 1500 miles. Thats about what I expected