mileage, programmer, what else?

[Brunner88]

2001 X

7.3 no mods
I would love to see a little better mileage...I know that is a difficult task given how heavy this mammoth is but if I could even net a few more mpg....I would smile.

What are some proven entry level programmers for this and what else do I need to entertain to get some better mileage?

Currently I can get nearly 19 mpg on the highway if I keep it below 2000 rpms. 2000 rpms is the key. If I cruise at 70 or more (more than 2k rpms) then it drops crazy. Like all the way to 13.6 Mpg.

Around town it sucks regardless of how light I go with the pedal.

I'm running 285 75 16 rubber

[USMC2001PSD7.3]

Try an intake and exhaust and see where that gets you before doing programming. Tuning is great but if it cant inhale and exhale it wont get the results you are after. 19 is pretty good thats about what I get if I keep it under 70. At 65 I can get almost 21 on long trips (2001 also). 19 is very respectable from an X so you are already off to a good start. I noticed better gains when I do modifications to make the airflow smoother as opposed to tuning. I have an AFE Stage II with 5in turbo back MBRP with no cat or muff and I combined that with a CFM+ manifold and deleted the air intake heater. I did notice a slight drop in boost but the airflow was much much better with the new manifold and AIH delete. The manifold is a little expensive for the gains it gets but it works great and doesn't look bad at all.
The big question is.............Will the amount of money you spend on mods justify the fuel savings over time? I am planning on more airflow mods next month that should completely open her up (38r turbo, bellowed up pipes, and ebpv delete with high flow outlet)
Feel free to PM me if you have any questions bud


O yea and dont forget a fuel additive. I use Diesel Kleen cetane booster every tank. You get a mileage boost and extra protection and lubrication to your fuel system since the ULSD fuel isn't designed with 7.3s in mind

[dmd]

You will never recoup the cost of upgrades with milage gains. These things are
big and heavy. The milage you are getting is pretty good.

If you want more power, then the upgrades are the way to get there. You will get
a fraction better milage, but not worth upgrading unless you want/need more power.

You can spend $1500 to get 1-MPG gain, easier to just drive a few MPH slower.

[USMC2001PSD7.3]

The very first trip I made in my truck I got 18.6 IIRC. That was with intake and exhaust. Cruise at that same speed now after mods and I might get around 20. So 1.5mpg gain worth the mods.....NOPE!
If I am taking a trip and worried about mileage I just drive slower. Best I ever did was a hair over 22 at 55-60mph around Ft Benning area.
I love the mods I have done and how my truck runs but I definitely did not do them all for mileage.
Its been said many many times but the best mpg mod is a light foot and a slower cruise speed.....and no cruise control either!


DMD how do you like the 38R and high flow outlet? Saw it in your sig and I am really looking forward to that mod going in with my BTS and up pipes.

[Brunner88]

usmc,

some things I have noticed are...
you are spot on accurate with the air flow. A dirty air filter on a 7.3 will hold a few mpg hostage. Much more sensitive than smaller engines...gas or diesel.

Winter fuel around here has so much additive in it and it results in lower mpg. I use Kleen as well but I've been thinking about something...what is the stuff they are putting in the diesel at the pump to prevent gelling. I'm not so certain it doesn't have the same properties as the Kleen white bottle stuff ...maybe it doesn't but there is something in that fuel for sure and a lot of it.

[Brunner88]

Originally Posted by dmd

You will never recoup the cost of upgrades with milage gains. These things are
big and heavy. The milage you are getting is pretty good.

If you want more power, then the upgrades are the way to get there. You will get
a fraction better milage, but not worth upgrading unless you want/need more power.

You can spend $1500 to get 1-MPG gain, easier to just drive a few MPH slower.

I have an uncle that has a 2000 f-250 crew short bed. 7.3 engine. He has a hypertech or something made like 6 years ago, down pipe, 4 inch exhaust. He is seeing low 20's. Stock tires. 4x4

Is his math or comp being retarded or will he see a little extra being a bit lighter than the X?

[USMC2001PSD7.3]

Im not really sure man I live in Alabama so it really doesn't stay too cold there. I know I see a mileage drop in the winter but I never have to use Kleen white bottle.
Its so hard with these mpg threads because everyone's truck reacts different and everybody lives in a different climate. Even if you and your neighbor have the exact same truck with the same mods and you drove both of them the exact same I bet they would get different mileage

[Brunner88]

Originally Posted by USMC2001PSD7.3

The very first trip I made in my truck I got 18.6 IIRC. That was with intake and exhaust. Cruise at that same speed now after mods and I might get around 20. So 1.5mpg gain worth the mods.....NOPE!
If I am taking a trip and worried about mileage I just drive slower. Best I ever did was a hair over 22 at 55-60mph around Ft Benning area.
I love the mods I have done and how my truck runs but I definitely did not do them all for mileage.
Its been said many many times but the best mpg mod is a light foot and a slower cruise speed.....and no cruise control either!


DMD how do you like the 38R and high flow outlet? Saw it in your sig and I am really looking forward to that mod going in with my BTS and up pipes.

usmc, if i keep it at 55mph on flat stretches....I can see low twenties. Once the rolling resistance has been eliminated and we are moving...I can reset the comp and drive flat for miles at 55. low 20's all day long.

Maybe I just need to drive slower and be happier. That is hard to do.

[USMC2001PSD7.3]

Yea man same here the two longest trips unloaded in my truck so far have been from north AL to SC. Its relatively flat and I kept it between 63-68 and got 20.3 hand calculated filling the tank up all the way to the neck. I am running slightly smaller tires than you (265/75/r16) but theyre all terrains. Havent done enough testing in that area to see how much difference that makes either. I am considering switching to highway tread and going slightly taller and about an inch skinnier in tire size. That should lower the RPMs a hair and skinnier is always better for mileage.

I may start doing some testing for all kinds of driving and calculate the fuel mileage. I keep a log book full of info on the truck and anytime any fluid gets changed, fuel up, and maintenance, it goes in the book. Its a great way to keep track of how far you go and what you did and what you added to the tank. I log the gallons of diesel and oz of fuel additive and see what works best.

[Brunner88]

Originally Posted by USMC2001PSD7.3

Yea man same here the two longest trips unloaded in my truck so far have been from north AL to SC. Its relatively flat and I kept it between 63-68 and got 20.3 hand calculated filling the tank up all the way to the neck. I am running slightly smaller tires than you (265/75/r16) but theyre all terrains. Havent done enough testing in that area to see how much difference that makes either. I am considering switching to highway tread and going slightly taller and about an inch skinnier in tire size. That should lower the RPMs a hair and skinnier is always better for mileage.

I may start doing some testing for all kinds of driving and calculate the fuel mileage. I keep a log book full of info on the truck and anytime any fluid gets changed, fuel up, and maintenance, it goes in the book. Its a great way to keep track of how far you go and what you did and what you added to the tank. I log the gallons of diesel and oz of fuel additive and see what works best.

usmc that is good. Tires I have are Michelen
LTX A/T2 | Michelin Tires

I have a ton of off roading experience and these do pretty good. I think the X would do good regardless because it is so heavy but I can basically travel in 2wd ...even in the snow and ice. Hard packed snow is trouble in most vehicles but the X just fires along. I did hit some ice one time on the highway and had it about sideways....but was able to hold the fort. That was a crazy day. I have pictures of all the vehicles along the road. Damn freezing rain.

In the deep goo of mud would be a different story. I might need to have a dozer on standby