400 Miles no matter what!

[golfpro2301]

After paying attention to how I drive the last 5 tanks or so I am getting a little confused on the fuel consumption of my 6.4. It seems no matter how I drive it the low fuel light always comes on between 395-405. I drive 50 miles round trip every day to work. 75% are on the interstate between 70-75. The rest is under 45 thru traffic lights. The result is 400 Miles. two days ago I had to make a long round trip on the interstate. I started with my tank 3/4 full and drove the trip there and back with cruise set at 74 the whole way. Had enough fuel left for the next day to drive to and from work and did so as stated above. Fuel light came at 402 Miles. Anyone have an idea. Below are the upgrade to the truck

2010 6.4 SCREW
350 rear block
2in level in front
Nitto Grapplers
EGR/*** ******
CAE
******* tuner running 275 tune

*Not complaining about my mpg. If I get 15 fine if I get more great but it seems like no matter if I baby it or give it some gas at the light each tank comes out the same*

 

[drunk on diesel]

fuel light is based off of average consumption, unless you're resetting your mileage every time you fill up

if you're getting 15 hand calc'd, you're doing pretty good

I have a bunch of tunes I've made for my reg cab. Some will show 18mpg on the dash, some will show 24+ on the highway.

They all get about 15-16 hand calc'd LOL

 

[Powerstroke Man 6.4]

15-16 HC is the norm, at the very best 17 if you drive like a grandpa LOL.

Spar-tan 310 F-350
CCSB
DRW
4.30's

 

[halltrash]

we just halve to accept the fact they get pucky mileage my old 7.3 got anywhere from 17 to 22 mpg. my 6.4 gets between 14.7 and 15.5 oh well thank you mr. epa

 

[golfpro2301]

So for the last month My cruise control hasnt worked. The ******* is throwing two codes. One is something to the effect of brake switch b and the other is a readiness test. I am assuming the brake switch is the problem and I will get to it sometime. Here is the unusual point to all this. I would always use the cruise control as it improves fuel economy. For the last month I havent had it and I have driven normal and my 2 tanks have come out to 446 and 439. Anyone have an answer to this?

 

[drunk on diesel]

cruise leaves the coast clutch engaged. it also fuels pretty hard on resume function.

 

[Dusten]

Here's the issue. A change of 1mpg only nets a total gain of 20-25 miles per tank based on how much fuel take. But that 1 MPG is a 7% change which is pretty big. 7% on something like a TDI jetta is 3 or 4 MPG. The MPG's on these trucks won't vary from high to low, especially with your driving habit.