[LREhp]

So I've had my truck for almost a month now. I've put almost 5,000 miles on it(including the 1,200 mile ride home).. It got about 15.5mpg from Florida to Georgia, cruising about 70mph.. This was 100% stock..
Then I put the tuner on it, just a simple plug in Superchips that came with the truck..
And it got about 16.5-17mpg on the rest of the ride back to Illinois. This was hand calculated and the dash was pretty darn close too..

Now, I just went to my cabin Labor Day. And with the cruise on 70 or less the whole 800 miles round trip.. I was down to 13.5-14mpg! I put a full turbo back exhaust on it, straight piped. And it still had the tuner on it..

So my thought is, either I need to put an intake on it to match the current exhaust flow. Or I have an injector going away?

What say you?:dunno:

 

[Dlp250]

Don't do anything to your intake, do a search on this forum and they can explain better but in short it's good up to 500 up. I have the same setup as you but and f250 and I just got close to 20 from Springfield il to Tallahasse fl.

Sorry but I can't explain the loss of mpg's, I can tell you I picked up 1 mpg just by not using cruise control and I was going about 65. Is it hard to start? Blowing smoke? Running rough?

Good luck maybe someone here knows how to help.

 

[macoyle]

cruise control is overrated, if your aware of what your right foot is doing you can get another 1-2mpg out of it

 

[LREhp]

Don't do anything to your intake, do a search on this forum and they can explain better but in short it's good up to 500 up. I have the same setup as you but and f250 and I just got close to 20 from Springfield il to Tallahasse fl.

Sorry but I can't explain the loss of mpg's, I can tell you I picked up 1 mpg just by not using cruise control and I was going about 65. Is it hard to start? Blowing smoke? Running rough?

Good luck maybe someone here knows how to help.

Yea my dad's 1 ton SRW short box get's 22, mines a dually with bigger gears so I know it won't get that good.

 

[the06wildebeast]

Do you have a good monitor? That'll really help figure out whats wrong with it. Not saying this will gain you lots but a good fuel additive, some Rev-X, and an SCT with custom tunes will go a long way. First priority has got to be the monitor though!

 

[LREhp]

I plan on doing the SCT this winter, I just don't know why it dropped so suddenly.
And I don't have any gauges yet, I planned on getting the Edge CTS insight when I do the SCT.

 

[bfrank81]

I plan on doing the SCT this winter, I just don't know why it dropped so suddenly.
And I don't have any gauges yet, I planned on getting the Edge CTS insight when I do the SCT.

Do the CTS first. Run your truck for a while just to make sure you don't have other issues like with your FICM before you start playing with the tunes.

 

[xjeeper]

Fuel quality here in Il. seems to vary greatly,since I moved here I have noticed that my mpg drops when filled with biodiesel blend(thepumps are marked 5% to20% so you do not know what you are getting). The popular wisdom is that the oem air filter will support up to 500hp, this is true,but so will an oem exhaust including the cat. Both the exhaust and intake provide some benefits ( I ran some dynotests on my first 6.0 for a magazine write up back in 04).

 

[Tonka1042]

Hi,

I have heard that gunked up EGR's can cause a loss in MPG's. I took mine off the other day is it was pretty nasty. I am going to clean it and see what happens, I have lost about 1.5 MPG since I have retired my old tow rig and started using my F350 6.0 more often. (I am only towing 7k# max at the moment, so I thought it would have no affect, I was wrong)

Also, I know that what ever they are putting in fuel now - a - days has been messing with everything, even my CJ5 w/ 4BT - which got 38ish MPG, is now down to 32ish.
So much for making the fuel better. Ford has recommended that I add Cetane additive to help keep it clean, about $10/bottle - treats 120 gallons, supposed to keep the EGR clean (or cleaner).

If you are towing, I read that ford every 400# added to the truck will decrease mileage by 1 MPG, I do not know where they got that number, but that came right out of the manual. Yes, I read the manual, pretty board when stopped in 4 hours of traffic.