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Discussion Starter #1
I just want to preface this with I didn't buy a 7.3 and put 37s and expect good mpgs. so i have 01 CCSB 7.3 with an 8" lift and 37x13.5R22. I was getting 11.87 mpgs around town and highway like 12.45 and that was with stock injectors, turbo leak, up pipe leaks and stupid hot tune with an edge tuner.

I just put in the KC 300x 63/73 turbo, 180/30 injectors, boost fooler, banjo bolts, fuel cross over, a few other little supporting things and have the tunes from full force and run the "daily tune". with all that being said I get the same exact MPGs.... now I have way more power as my truck runs way better but i'd thought is at least get 15/16 mpgs. does this sound normal to y'all or do think something isn't right that's causing these lower mpgs.

Thanks,
Mark
 

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I get better mileage than that pulling a car trailer, so I have to think something is wrong. I would start with making sure you have no boost leaks and check to make sure your exhaust back pressure tube is intact and clear. Do you have gauges? A scanner? I would want to see a few runs watching boost, EB pressure, IC pressure, IPR duty cycle, etc. Something is going on there.
 

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With a 8" lift and 37" tires you are now driving a brick down the road. The wind resistance alone will kill the mpg.

Did you ever re-calibrate the the speedometer for the bigger tires? How are you figuring your mpg, the lie-o-meter or by hand?
 

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Discussion Starter #4
Yes I have a boost gauge and i building the correct boost ( I think lol)

I know I am driving a brick but my truck was getting just as good mpgs before with an exhaust leak, stock injectors, and that stupid tune.

the speedometer is correct and I am tracking the mpgs by hand.
 

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and check to make sure your exhaust back pressure tube is intact and clear.
X2 This probably made the biggest difference with my trucks mpg - my ebp tube was clogged with soot and sensor was bad.
 

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X2 This probably made the biggest difference with my trucks mpg - my ebp tube was clogged with soot and sensor was bad.
Can I ask how much improvement it made for you?

I replaced a tube and sensor on a 2000 and it didn’t seem to make any difference. I first cleaned the tube by routing it out but when I sprayed some Bar-B-Q cleaner into the tube to loosen up the carbon, it dripped out one of the bends in the tubing and only then did I spot some small pinholes. If I had not poured fluid into the tube I never would have seen those holes.
 

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Can I ask how much improvement it made for you?
Arctic, I’m sure you know more about these engines than I do- I wish I had been more scientific in my upgrades/deletes and data collecting. But I actually did several things at the same exact time: intake air heater delete, replaced ebp tube & sensor, and TS-6 tuner. My net gain by math was 3 more mpg. Most of my driving is empty. (When towing my boat trailer (3500 lbs.) my best results have been in the +50 hp tow tune 14-15 mpg) I have learned that the tuner by itself really doesn’t change mpg between tunes when empty if I drive conservatively, the IAH delete is only opening up a small restriction which leaves me to believe the ebp tube/sensor was most responsible for the gain.
Since buying the truck in ‘18 (185k) I have also done the zoodad, muffler delete (went to walker BTM) and other items in my signature, over time I have went from 14mpg when bought to 18 and sometimes 19 mpg with summer grade diesel. I have a 2002 F150 with the 4.2 V6 and have always gotten around 17mpg and far worse pulling the boat so I’m very happy with the mpg’s on the F350.

I am also driving almost all flat, some hills (Illinois) so I’m sure that is a factor as well.
 

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What type of speeds are you driving and what is the axle ratio? I would not expect injectors especially bigger ones to get better MPG. The tall tires will help with gearing and RPM but the drag of wider tire hurts MPG. Jacking a truck up really hurts MPG due to the amount of drag you are creating. If you want good MPG look up posts from Phil Whitmore (I think I have the name right. He did extensive testing and some great info. I would expect little or no MPG increase from a tuner/exhaust/intake/or anything else you added. If you got some it is not cumulative between the mods. The venders will say you can improve MPG with most of all the mods. But even if they all could do 1mpg each. once the first mpg is reached the usually the rest give nothing or only a 1/10 of a mile. Power is in the same boat. first 50 HP from a tune is not that hard but once you have it. the rest of the mods do little except control EGT. With a stock SRW 01 and 3.73 gears you should get around 19-20 MPG at 55 MPH. Every 5 MPH above that will usually cost 1 MPG. Add DRW/4.10 axle/big tires/lift, it is very easy to quickly drop MPG. I have had 4 7.3 Fords over the years and done lots of mods some did give some nice power increase and EGT decrease but I don't thing any helped MPG on any of my trucks.
DENNY
 

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Big Horn, I am always trying to learn —just like yourself. I think your EBP improvement was more typical and also helpful to the OP.

Denny sums it up best: the surest way to improve economy comes from the foot ;-)
 
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