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Discussion Starter · #1 ·
Why does my 06 5.9 24v get 15mpg with NO LOAD, always now at mostly city driving? Highway is more like 17. My dads ford 250 6.7 1986 gets 25 highway all the time. WHATS UP DODGE!?

1. 06 5.9 24v, mega cab, 4wd, 130k miles
2. oil cap has zero blowby
3. stock rims, stock type AT tires
4. i just replaced the AFE filter on aftermarket intake. The original had the extra surface area of filter material on the tip, but this new one does NOT.
5. has duel exhaust upgrade, quite loud
6. it sounds healthy, but Im not real familiar with cummins.
7. Have not taken it to a mechanic yet, for inspection or anything.
8. A/C compressor clutch locked up, but pulley is still spinning.
9. EDGE gauge shows trans temp hitting 215 on hills in summer OFTEN.
10. ANY IDEAS WHY 15mpg?

Is this old school EDGE EZ & EVOLUTION programmer causing issues? Is it the hills/mountains I drive everyday?

When I purchased the truck 1yr ago the gauge on ceiling usually showed 17.5, but 3 months ago, I dumped 1 small jug of cummins injector cleaner in the tank, went through the entire tank and replaced intake filter. Now at this point Im at 15mpg on ceiling gauge. I have not actually checked the numbers ever, manually lol. I need to do that of course.

Thanks for any insights :)

931222
 

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Rear Admiral Rickard Onmi
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the lie-o-meter will never tell the truth. Hand calculate and come back with actual numbers
 

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Discussion Starter · #3 ·
the lie-o-meter will never tell the truth. Hand calculate and come back with actual numbers
Ya, I had wanted to check manually, but I hardly drive the truck, so I'd prob have to wait a good month or more to get some accurate numbers. I should have written it down long ago tho. Is there a rule of thumb to how much that gauge is usually off by? 2mpg? Any other thoughts? TY
 

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05-CR, 6 Spd std, 4x4, level kit. Colt stg 3 cam, billet turbo, 4” exh, smarty, ARP studs, 35” boots
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My lie-o-meter is consistently out by 10-14%.
I’m actually getting better than it reads.
I can’t tell you if they are all like that, but inaccuracy is the consensus.
 

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The lie-o-meter typically reads higher than actual. So if it’s reporting 15 your likely getting 12 or so when you hand calculate.

Why? It could be mechanical, but more likely driving conditions. A lot of stop and go, stop lights, accelerating from zero, idling and short trips, will keep your average mpg pretty low.

Example, I gained 3-5 mpg (no joke) when I moved to Texas where there is less stoping, longer highways runs, generally slower freeway traffic. That said I use as much fuel because every trip is more miles, but at least it’s cheaper fuel.

so.. get some hand calculated number over a few ranks. Top off the same every tank and report back, but chances are all is normal. honestly 15 average is not horrible, depending on your driving conditions.

I should have written it down long ago tho. Is there a rule of thumb to how much that gauge is usually off by? 2mpg? Any other thoughts? TY
no not really, seems like most report it reading higher than real, but some say it reads lower.

On mine, when in town stop and go driving it gets real bad, like 4mpg higher than actual. In long highways runs its only 1-2mog high. Funny because towing long trips it likes to actually read lower than hand calculations, figure than one lol..
 

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15/17 would be a normal mpg for the truck. You can be doing better on the hwy, but in genersl, those numbers are on target.

Factors such as RPM and stop and go traffic deplete efficiency. There are other factors as well, but those two are the factors I have the most control over as a driver.

But firstly, start hand calculating your mileage. The overhead, I found, is mostly good for trends.
 

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Discussion Starter · #8 ·
Thanks for the input. So, 15/17 may be accurate for an auto mega 06 5.9? Man, that's not what I was aware of when I bought the truck lol. I was hoping for at least 20.

So, what do you guys usually get when you're loaded? Full load of dirt in the bed? 10k trailer mpg? Does it get down to 10mpg and worse?

Maybe I should get rid of the catalytic converter if its in there? The truck has dual catback exhaust, but I believe theres what looks like a cat on this 06.

One of these days, Ill report back with some numbers. Maybe whine some more ;)
 

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Thanks for the input. So, 15/17 may be accurate for an auto mega 06 5.9? Man, that's not what I was aware of when I bought the truck lol. I was hoping for at least 20.

So, what do you guys usually get when you're loaded? Full load of dirt in the bed? 10k trailer mpg? Does it get down to 10mpg and worse?

Maybe I should get rid of the catalytic converter if its in there? The truck has dual catback exhaust, but I believe theres what looks like a cat on this 06.

One of these days, Ill report back with some numbers. Maybe whine some more ;)
Yea bud, so many people IRL and on the interwebs like to “fluff” their mpg numbers or just spout out the lie-o-meter like it’s gospel. Or they fail divulge their crazy OCD to mpg watching and perfect “ideal” driving conditions that result in crazy good numbers. It generally gives people wrong idea.

to be fair now… my buddies Tacoma averages 14-15, he hand calculates. My uncles f150 with a tiny little 2.7 eco boost is averaging him 23-25mpg hand calculated doing about the same driving I’m doing. So 15-20mpg unloaded in a 4wd 7500# truck that can pull a house is pretty impressive, not something as easily achieved by the other diesels options.

Want better? Slow down, coast more, accelerate easier, get a solid tune and keep the truck maintained. Keeping the tire size and tire weight down goes along way too. Most of the crap people do to save a few pennies in fuel does not have a ROI in actually fuel savings.

I hear if you put a Prius barge on the side and duct tape the gap between the cab and bed you gain 11mpg ;)
 

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FYI, since you asked, I normally average 12mpg towing on a good trip. 9-10 with a lot of head wind and 7-8 when my wife’s drives, she seems to love WOT.
 

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AT tires a bad choice. That’s 1.5-2.0/MPG to the annual average. (Serious mistake). “Best” is closed-shoulder, highway-rib.

Tire pressure to spec (not high or low). Needs weight scale axle reading to get loads.

Verify alignment correct

Verify ZERO steering play

Verify ZERO brake caliper drag

Verify ZERO CAC leaks

Verify Auto trans working properly.

No air filter restriction

Run double dose of POWER SERVICE (silver container; at Wally)

Maximize steady-state cruise.

The average over 3-5,000-miles is what counts, not tank-by-tank.

One gives a damn about fuel economy — is willing to chase details and reform driving habits — or he’s a whiny *****.

Industry studies show that the driver is one-third the FE equation. Vehicle spec can’t be changed, nor climate/topography at all. The competition is against ones self.

Tires, plus driver is “it” (truck otherwise like new). Have a plan.

Diesel pickup owners operate the same as when it was Mommy’s Camry they were driving: poorly.

It’s not a car.

Nor should you assume you “know” how to drive. Tires & brakes should last in excess of 70k miles (100k once you figure it out).

FE — like tire/brake life — is an indicator of operator skill.

Those who say they didn’t buy it for FE are at the low end of the scale for owner-operator skill. Ghetto “skillz”. (Lack of skill is the norm).

Among big truck drivers it’s the owner-operators who’ve learned what works, what doesn’t, and get highest MPG.

The truck will tell you what it wants. You provide steering & braking inputs. Let the computer run the drivetrain is an example of how to succeed: highway = cruise control exclusively. Drive below the flow. Never change lanes, never use brakes or accelerate. CC on at entrance ramp and never off till exiting highway (rural).

Get out notebook and let ideas flow. Problem is YOU (not the truck once like-new again).
 

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05-CR, 6 Spd std, 4x4, level kit. Colt stg 3 cam, billet turbo, 4” exh, smarty, ARP studs, 35” boots
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All good points.
i swapped out my emissions cam shaft for a Colt stage 3. The engine pulls like a freight train, from 1600 RPM right to 2800. Pulling my 15,000 LB toy hauler, I now get 14 mpg, as opposed to the 10 that I got before. Empty, I lost 3 mpg (20 down to 17)..... I tow only 10% of my annual miles. I’m happy, but economically it was a bad choice
 

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but economically it was a bad choice
IDK, economically I could never make the math work to own a second vehicle. If you need a truck you need a truck. insurance, maintenance, driveway space, gasoline... none it of it added up to less than my fuel costs to just drive my Truck everywhere. maybe break even at best. But id just assume have one thing I drive.
 

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Lots of good info in 04CTD's post above. Lots of things you can check, but driving style plays a big part as well.

All highway I can get 21-22 mpg. Running county roads empty I normally average around 17-18. Moderate load takes me down to 14. My heaviest loads, 15k-20k, drops me below 10 mpg.
My truck is not my daily driver, and spends most of it's life hooked to my trailer hauling hay or something. So I'm not super concerned about maximizing mpg. That's what I have a TDI for.

I do recommend downloading the Fuelly app on your phone. Input your odometer reading and gallons at each fuel-up. Keeps track of your fuel economy, prices, and you can input reminders for oil changes, tire rotations, flushing engine coolant, etc. Sure makes keeping track of multiple vehicles easier.
 

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You need a stick shift for MPG in the 20s with a 4x4. I can barely break into the 20s with an OEM 2006 Muffler, 4 inch downpipe and exhaust, AFE Bladerunner turbo, and Edge Evo Tow tune (mpg tunes have way too much timing imo). I also run PS injector cleaner which adds like 1 mpg, and you're probably not going to hit the 20s with the AC comp running. 285 falken all terrain tires with a nv4500 and 3.73s, straight tread isnt an option in 2 feet of snow. And an incredibly rare combo only offered for one year. Your truck may have 4.10s
[/QUOTE
Lots of good info in 04CTD's post above. Lots of things you can check, but driving style plays a big part as well.

All highway I can get 21-22 mpg. Running county roads empty I normally average around 17-18. Moderate load takes me down to 14. My heaviest loads, 15k-20k, drops me below 10 mpg.
My truck is not my daily driver, and spends most of it's life hooked to my trailer hauling hay or something. So I'm not super concerned about maximizing mpg. That's what I have a TDI for.

I do recommend downloading the Fuelly app on your phone. Input your odometer reading and gallons at each fuel-up. Keeps track of your fuel economy, prices, and you can input reminders for oil changes, tire rotations, flushing engine coolant, etc. Sure makes keeping track of multiple vehicles easier.
Your dad's 1986 doesn't have a 6.7 in it.
Why does my 06 5.9 24v get 15mpg with NO LOAD, always now at mostly city driving? Highway is more like 17. My dads ford 250 6.7 1986 gets 25 highway all the time. WHATS UP DODGE!?

1. 06 5.9 24v, mega cab, 4wd, 130k miles
2. oil cap has zero blowby
3. stock rims, stock type AT tires
4. i just replaced the AFE filter on aftermarket intake. The original had the extra surface area of filter material on the tip, but this new one does NOT.
5. has duel exhaust upgrade, quite loud
6. it sounds healthy, but Im not real familiar with cummins.
7. Have not taken it to a mechanic yet, for inspection or anything.
8. A/C compressor clutch locked up, but pulley is still spinning.
9. EDGE gauge shows trans temp hitting 215 on hills in summer OFTEN.
10. ANY IDEAS WHY 15mpg?

Is this old school EDGE EZ & EVOLUTION programmer causing issues? Is it the hills/mountains I drive everyday?

When I purchased the truck 1yr ago the gauge on ceiling usually showed 17.5, but 3 months ago, I dumped 1 small jug of cummins injector cleaner in the tank, went through the entire tank and replaced intake filter. Now at this point Im at 15mpg on ceiling gauge. I have not actually checked the numbers ever, manually lol. I need to do that of course.

Thanks for any insights :)

View attachment 931222
Your dad's 1986 F-250 doesn't have a 6.7 in it. My neighbors 2018 6.7 gets mediocre fuel economy in town. My other friend's 2001 F-250 has always gotten 14-16 mpg max and he's got 265's.
 

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05-CR, 6 Spd std, 4x4, level kit. Colt stg 3 cam, billet turbo, 4” exh, smarty, ARP studs, 35” boots
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IDK, economically I could never make the math work to own a second vehicle. If you need a truck you need a truck. insurance, maintenance, driveway space, gasoline... none it of it added up to less than my fuel costs to just drive my Truck everywhere. maybe break even at best. But id just assume have one thing I drive.
I’m a auto junkie. Not an economics major.
I have several cars, trucks, jeeps and motorcycles. To justify it.....I drive em all
 

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Discussion Starter · #17 ·
Thanks for your thoughts. I just downloaded a fuel mileage app to make things more accurate. Should have done that long ago.

Yes, his 1986 250 get 25mpg highway and has a Diesel 6.X. I was hunting for a 250 diesel until friends kept telling me Id be unhappy fixing it constantly. So, I found a good deal on the 06 ctd and went with it. buddy has a single cab 6.7 07 CTD which gets 20mpg. Of course it's a bit lighter.

Ill chime in again once I have more numbers and replace the possible drag pulleys and ac comp.

Yes, checking all possible drag like brakes is a fun idea.
Yes, checking for boost leaks is a great idea.
Yes, I did run 1 32oz jug of Diesel Kleen through a full 34g tank. I did not try double.
I have steering play, too much in my opinion, but the recall was fixed i believe already. I dont know how much is normal in the 06 ctd

My disks and ceramic breaks are all brand new, mopar. But SQUEAL for the entire time Ive owned the truck, 1 year! I WISH I COULD SOLVE THAT! Squeal goes away after hours of driving, but always squeals when braking from start of trip for a while. I feel like it wasn't installed right. They should have used some lube or SOMETHING. Im not familiar with brakes enough to know if theres some lube to use. Maybe i should spray some brake cleaner all over.
 

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05-CR, 6 Spd std, 4x4, level kit. Colt stg 3 cam, billet turbo, 4” exh, smarty, ARP studs, 35” boots
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Thanks for your thoughts. I just downloaded a fuel mileage app to make things more accurate. Should have done that long ago.

Yes, his 1986 250 get 25mpg highway and has a Diesel 6.X. I was hunting for a 250 diesel until friends kept telling me Id be unhappy fixing it constantly. So, I found a good deal on the 06 ctd and went with it. buddy has a single cab 6.7 07 CTD which gets 20mpg. Of course it's a bit lighter.

Ill chime in again once I have more numbers and replace the possible drag pulleys and ac comp.

Yes, checking all possible drag like brakes is a fun idea.
Yes, checking for boost leaks is a great idea.
Yes, I did run 1 32oz jug of Diesel Kleen through a full 34g tank. I did not try double.
I have steering play, too much in my opinion, but the recall was fixed i believe already. I dont know how much is normal in the 06 ctd

My disks and ceramic breaks are all brand new, mopar. But SQUEAL for the entire time Ive owned the truck, 1 year! I WISH I COULD SOLVE THAT! Squeal goes away after hours of driving, but always squeals when braking from start of trip for a while. I feel like it wasn't installed right. They should have used some lube or SOMETHING. Im not familiar with brakes enough to know if theres some lube to use. Maybe i should spray some brake cleaner all over.
Ceramic brakes are not engineered for “truck” type of driving. They only work well when they are hot, and ALWAYS squeak when cold.
my recommendation, based on experience, is to use a reybestos semi metallic brake pad, over a slotted, vented, cross drilled rotor.
Don’t allow the pads to wear beyond 75-80% of original material thickness... replace them. They are cheap, work well, and aren’t usually noisy. The rotors that I’ve suggested are expensive, and you can’t machine them.
Run a scotch brite cookie on your die grinder over them to clean up the glazing, between pad changes. I get about 3 pad changes on a rotor. Depending on how and where you drive, that could be 200,000 miles ??
that’s only my suggestion. I’m sure others here have similar experiences (or different)

There have been a lot of great suggestions on here already about your fuel economy.
I just try to remember that I’m driving a 7500 LB truck, and I own it solely because I have a 15,000 LB 5th that I pull once in awhile... and that comes at a price.
If I cared about it that much, I’d buy a Prius, rent hotels to offset the cost of having the camper, and be in a similar financial place.
but have a real problem stuffing my balls into my wife’s purse.... so no Prius... lol
 

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@FKDWG

Please don't put your reply to a quote within the QUOTE tags.
Put it after the last tag.
Makes it a whole lot easier to read.
 

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But SQUEAL for the entire time Ive owned the truck, 1 year! I WISH I COULD SOLVE THAT!
You use the brakes lightly too much. A couple of heavy braking stops usually will clear that up.
 
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