Tweaking for best Fuel Economy??

[cleatus12r]

Originally Posted by soutthpaw

but it would only be Doggy in that light throttle/2000rpm range... Maybe I just need to run 1 tank on the stock setting there is about as much chance of that happening as there is of me being able to keep the cruise at 65mph which would probably net a nice MPG increase... It's really disheartening concerning the mileage increase when slowing down. If I drive 75, then I can get 16-17 MPG. But since I mostly drive 65-68 MPH, I can usually do 19.5-21 depending on whether I drive east or west (slight upslope driving west).

I don't even have the stock tune loaded. I did previously and don't think i ever ran it for more than about a minute before i had to go back to the 100 or even the FS tune. If i could get the throttle response to be a little better in stock I might be able to put up with it for a tankful... You can...the Mass Fuel Desired map along with the LBF map will make "stock" run pretty well. Also increasing the desired ICP 100-200 PSI in those certain operating conditions helps too. I don't think I'd run too much extra, but a little would be better. Don't know how I even lived with my 2 previous trucks that had the 7.3 stocker in them..It's weird because I have all of this stuff.....but I run "chipless" most of the time. It seems backwards but the factory did a pretty good job. I am just gonna hate driving my 4700 International once I get it done. So will definitely have to pull the PCM and ship it to Bill so he can see what he can do with it...

So based on what u said in your reply, maybe I should start by dropping the PW Multiplier values down about 10% or so under about ICP of 13.
Is the low boost fuel just a maximum limit setting for said parameters or does it actually command that amount of fuel? If its just a limit then I can see it would probably not affect cruising MPG..I'm no expert and I could be bass-ackwards. I'd call Bill next week and ask him. I am probably way off base. I would ASSUME that the LBF table works in conjunction with the Fuel limit vs. RPM map. I believe it's a percentage.....and yes, you can run 100+ in those tables. However, I don't recommend it because it can make the truck a little TOO responsive.

Here you go.

Your best bet is to talk to Bill.

[soutthpaw]

I made a couple of tunes and tried them but just didn't cut it... I like the get up and go too muchso i went with the 60, 80 and 100... dropped the FS as it really does not seem to make much difference... looking at the Fueling maps it looks like the 60hp would be pretty economical as it really doesn't add much fuel compared to the 80 and up... Im gonna try these for a while and see....

[soutthpaw]

Well I have been limiting myself to driving 65 or slower this tank of fuel and it looks like I am in for an increase in MPG. I have been running the 100HP tune... maybe I need to merge the shift maps from the FS with the 100hp tune for more mpg.

Might try tweaking the ICP up a bit and the pulse width down a tad too..

Oh does anyone know how Ford's Lie-O-Meter actually caluclates the MPG estimates (which values it uses etc)

[cleatus12r]

Originally Posted by soutthpaw

Oh does anyone know how Ford's Lie-O-Meter actually caluclates the MPG estimates (which values it uses etc)

Here's the technical part:


fuel level sensor data
Data Output Line (DOL) fuel flow data from the PCM
vehicle speed signal