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Discussion Starter #1 (Edited)
Curious as to what the consensus is on why some trucks get better mileage than others. I am guessing its the engine management systems and components rather than the overall truck itself or the basic longblock of the engine. I am looking for everyones thoughts on what they think makes the difference in equally optioned trucks getting varying mileage results.
Say for instance if you change out a bare long block using your current engine managements systems (sensors, injectors, ficm, etc) you should retain the same basic mpgs i would think. Taking into account of course you are replacing an engine due to catastrophic failure that ran fine prior to failure vs replacing an old high mile worn out low compression or dusted engine which has lost its efficiency.

For instance my 03 6.0 dually 2wd crew cab bone stock with 4:10 axle ratio will get 19 hand calculated at 70 mph and 22.5-22.9 hand calculated at 60 mph. These figures are running interstate with no stops between fillups going cross country. I want to do some work to the truck including egr delete 4" exhaust and a tuner. I have recently purchased a gear vendors overdrive since i have 4:10's but havent as of yet installed it. so looking forward to what my end results will be.
 

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Using stock trucks as a standard to apply I'd say first it's geographical location. Second is the driver. Third I would suspect the components of the motor.

With that being said there are several different PCM strategies that were/are applied across all the different year motors. So while there may be two trucks from the same model year they may have come off the line with two different PCM codes.

I have a Job2 2006 that I originally bought in TN. I have NEVER allowed the dealership to reflash the PCM. I have always gotten between 14-18MPG (HWY or City) even with all my mods. Wish I could say what it takes to get better MPGs but if I did I would share it with all.
 

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Geographical location with regards to elevation, heat, etc? or with regards to different computer flashes for different parts of the country from the diesel?

Is our fuel generally all the same across the country? My guess would be no...
 

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Geographical location with regards to elevation, heat, etc? or with regards to different computer flashes for different parts of the country from the diesel?

Is our fuel generally all the same across the country? My guess would be no...
Yes..geographically. CO peeps are going to run different than FL peeps.
Computer flashes may be part of that as well. Since CA has a TON of emissions over say Lower AL.

I have heard the fuel refineries do make different fuel formulas for different regions. I can't confirm that info but it makes sense to me.
 

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FICM was reprogrammed by Ford and when you brought it in for even an oil change, Ford mandated the Tech Flashed them like it or not 5mpg decrease, this was to save the motor.
 

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Personally I have driven the exact same truck (gasser) and get different mpg's. I think the main question is does the same truck with the same driving style get different mileage. For me the answer is 100% yes. I have seen up to 1.5 mpg difference in fleet vehicles with the same mileage.

This is not to say geographic location (hills, fuel, roads, climate, altitude) don't play a role as well. For instance I drove from Illinois to Florida last week 900mls at 65 the whole way and on the first tank I got 19.5 and on the second tank I got 20.4, this was all in the same day. Also a good tailwind could have made the difference as well.

What I would lime to know is how are the 7.3's getting the same or better mileage as me. I know all the emissions crap, but specifically....what? If it is a physical part why hasn't aftermarket come out with a fix, the same can can be said with the programing?
 

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Biggest thing is the geographic area, primarily relation in altitude and the grades traveled, and then the relative heat. Each would greatly impact the mileage on these trucks.

Then it would be driving style, which is obvious.

Third would be the specific strategy the truck is running. And Ford can't flash the customer to a newer strategy without their knowledge (depending on state law, its performing work without the owners consent). I also take that one step further with every work order I sign stating "Do Not Reflash." The newer the flash, the worse the mileage for the most part.

The last factor, and it may play such an insignificant amount to be ruled irrelevant. Is each tankfuls specific gravity and blend, and weather an additive is used. Throughout the year, I make it a point to fuel early in the morning whenever possible. This ensures I get most fuel per gallon (in relation to density), and I run the appropriate Diesel Klean additive for the season.
 

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Just got back from a trip to Wisconsin drove about 2000 miles total. I was driving my 2005 F250 4x4 supercab with 3.73 gears and around 100,000 miles. Got 20-21 when driving 65-72 mph. Mileage dropped to 18-19 when driving 75 mph plus. The key was keeping the rpm under 2100 rpm.
 

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Third would be the specific strategy the truck is running. And Ford can't flash the customer to a newer strategy without their knowledge (depending on state law, its performing work without the owners consent). I also take that one step further with every work order I sign stating "Do Not Reflash." The newer the flash, the worse the mileage for the most part.

The last factor, and it may play such an insignificant amount to be ruled irrelevant. Is each tankfuls specific gravity and blend, and weather an additive is used. Throughout the year, I make it a point to fuel early in the morning whenever possible. This ensures I get most fuel per gallon (in relation to density), and I run the appropriate Diesel Klean additive for the season.
Not according to this...FICM might fall under a different catergory than the ECM.

Power Hungry Performance - FICM Reprogramming

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When it was released, the '03 6.0L Power Stroke was an impressive powerhouse. Variable Vane Turbo technology and 4 valve heads helped the engine produce power levels that would overshadow the earlier 7.3L Power Stroke engines. Unfortunately, it was equally plagued with mechanical failures. This, combined with an inadequate supply of replacement parts, gave the early 6.0L a horrible reputation among Ford enthusiasts.

2005 saw the release of the redesigned 6.0L engine with radical changes to the cylinder heads which helped improve head gasket sealing and virtually eliminated coolant leaks. Unfortunately, this year also saw the release of Engine Control Module (ECM) and Fuel Injection Control Module (FICM) updates that limited power output of the engine and severely degraded fuel economy. Also, in an effort to reduce further issues on the '03 and '04 model years, the same power limiting calibrations were loaded into any vehicle that happened to wander into a Ford dealership for service. Often, these "updates" were applied without the knowledge (or approval) of the vehicle owners. Imagine the surprise of 6.0L owners everywhere who went in for a simple oil change and lost 3-5 MPG INSTANTLY!
 

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Well, I can't add much except to say, when I keep my foot out of it, my milage improves. :)
I'm too stoopid and immature to get good mileage :doh: Something about having the ability to shock the heck out of that guy in the 2 door coupe at the light, that you KNOW has done something to increase performance, keeps getting in the way of me breaking 16 MPG :doh::tard:
 
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