MPG issues
Thread Starter
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Tuned
Joined: Feb 2006
Posts: 354
Likes: 9
MPG issues
To begin with,, ‘00 F250, super crew, 4x4, 320k miles, 3.73 gears on stock tires with a Superchips Tow Safe tune, big tractor filter (sorry, forgot #), Rotella Synthetic oil, regular maintenance and filter changes.
I can fuel fuel up at same pump. Drive the same roads, the same driving behavior, and see major differences in MPGs.for example: towed bass boat at speeds between 50-65 for 150 miles. Got 16.5 mpg. Made same trip weeks later, 13.2! Same goes with running empty...
Engine starts easily, runs strong, solid fuel pressure, etc. just ****ty mpg’s that are inconsistent.
Any suggestions or ideas?
I can fuel fuel up at same pump. Drive the same roads, the same driving behavior, and see major differences in MPGs.for example: towed bass boat at speeds between 50-65 for 150 miles. Got 16.5 mpg. Made same trip weeks later, 13.2! Same goes with running empty...
Engine starts easily, runs strong, solid fuel pressure, etc. just ****ty mpg’s that are inconsistent.
Any suggestions or ideas?
Thread Starter
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Tuned
Joined: Feb 2006
Posts: 354
Likes: 9
Yes, hand calculated and the fill ups have been at the same pump.
FTE Leadership Emeritus
Joined: Sep 2003
Posts: 12,241
Likes: 755
From: Houston, Texas
Did you also remove the mixing valves and put in a pre-pump filter? It's easier to change the pre-pump filter than it is to change the mixing valve filters.
You may also be dealing with subpar diesel too. Certain stations I fill up at, the truck likes. Other stations, the truck despises.
Flying J sometimes has B5-20 and both my Diesel Excursions like it. What may help you is Archoil AR6200. It's a fuel catalyst that improves the quality of subpar fuel. It worked well in my 6.0 Excursion on a road trip to San Antonio. It gave me a solid 18-19 mpg on a trip it would normally give me 15 to barely 17 mpg. (I later found out this was related to the heads not being torqued properly).
Give it a shot, you can get it on Amazon easy.
You may also be dealing with subpar diesel too. Certain stations I fill up at, the truck likes. Other stations, the truck despises.
Flying J sometimes has B5-20 and both my Diesel Excursions like it. What may help you is Archoil AR6200. It's a fuel catalyst that improves the quality of subpar fuel. It worked well in my 6.0 Excursion on a road trip to San Antonio. It gave me a solid 18-19 mpg on a trip it would normally give me 15 to barely 17 mpg. (I later found out this was related to the heads not being torqued properly).
Give it a shot, you can get it on Amazon easy.
Laughing Gas
Joined: May 2007
Posts: 793
Likes: 29
At the risk of insulting and expanding on the question about filling... Are you dribbling in the last gallons of fuel so that the fuel comes all the way up the filler tube, or letting the pump click-off on its own?
And toward the various mileage readings, are they all on the same grade of fuel? Meaning that even though the fuel comes from the same pump, the actual fuel might be different based on summer and winter blends.
And toward the mileage observations, I will argue that 16.5 while pulling a boat is about right. Especially if this is with a slushbox.
And toward the various mileage readings, are they all on the same grade of fuel? Meaning that even though the fuel comes from the same pump, the actual fuel might be different based on summer and winter blends.
And toward the mileage observations, I will argue that 16.5 while pulling a boat is about right. Especially if this is with a slushbox.
Thread Starter
|
Tuned
Joined: Feb 2006
Posts: 354
Likes: 9
Did you also remove the mixing valves and put in a pre-pump filter? It's easier to change the pre-pump filter than it is to change the mixing valve filters.
You may also be dealing with subpar diesel too. Certain stations I fill up at, the truck likes. Other stations, the truck despises.
Flying J sometimes has B5-20 and both my Diesel Excursions like it. What may help you is Archoil AR6200. It's a fuel catalyst that improves the quality of subpar fuel. It worked well in my 6.0 Excursion on a road trip to San Antonio. It gave me a solid 18-19 mpg on a trip it would normally give me 15 to barely 17 mpg. (I later found out this was related to the heads not being torqued properly).
Give it a shot, you can get it on Amazon easy.
You may also be dealing with subpar diesel too. Certain stations I fill up at, the truck likes. Other stations, the truck despises.
Flying J sometimes has B5-20 and both my Diesel Excursions like it. What may help you is Archoil AR6200. It's a fuel catalyst that improves the quality of subpar fuel. It worked well in my 6.0 Excursion on a road trip to San Antonio. It gave me a solid 18-19 mpg on a trip it would normally give me 15 to barely 17 mpg. (I later found out this was related to the heads not being torqued properly).
Give it a shot, you can get it on Amazon easy.
I don’t have a pre-pump filter. I’ve had the in tank screens out and cleaned them a year or so ago. (Is that the mixing valve you speak of?
You may be correct about the sub-par diesel. That’s been a concern I’ve had for awhile. I live in MO,, and I know the gasoline blends here suck!
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Thread Starter
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Tuned
Joined: Feb 2006
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At the risk of insulting and expanding on the question about filling... Are you dribbling in the last gallons of fuel so that the fuel comes all the way up the filler tube, or letting the pump click-off on its own?
And toward the various mileage readings, are they all on the same grade of fuel? Meaning that even though the fuel comes from the same pump, the actual fuel might be different based on summer and winter blends.
And toward the mileage observations, I will argue that 16.5 while pulling a boat is about right. Especially if this is with a slushbox.
And toward the various mileage readings, are they all on the same grade of fuel? Meaning that even though the fuel comes from the same pump, the actual fuel might be different based on summer and winter blends.
And toward the mileage observations, I will argue that 16.5 while pulling a boat is about right. Especially if this is with a slushbox.
No insult taken.. just looking for answers. As for the same grade of fuel, who knows. I fuel at the same location the majority of the time. (Not sure their fuel blend ea load they get). And this is on summer diesel. When fueling I push fuel into the neck until the nozzle pops a couple times.
And thats the best I’ve gotten with a boat. Can barely touch that empty on highway. I average around 13-14 city/ highway. And maybe 14-15 highway, and that’s keeping it under 70
plz educate me “slushbox”? Auto tranny?
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Tuned
Joined: Apr 2009
Posts: 394
Likes: 1
From: DFW
I had real poor mileage in cool weather, I blamed the winter diesel. Summer was better but still not great mileage. Turned out the
thermostat was broke. All the gauges show fine but the engine was not warming up well. I gained 2-mpg in town and can get
even better gains on long drives. Might be worth checking.
thermostat was broke. All the gauges show fine but the engine was not warming up well. I gained 2-mpg in town and can get
even better gains on long drives. Might be worth checking.
Cargo Master
Joined: Apr 2007
Posts: 2,333
Likes: 1
From: St. Louis, Mo.
I know from towing for years that a strong headwind or tailwind can make a 2 mpg difference real easy,but thats pulling a fifth wheel trailer. Dont know what else to make that much difference. Make sure you dont have a brake sticking/ letting loose intermittantly- (slidepins).
Thread Starter
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Tuned
Joined: Feb 2006
Posts: 354
Likes: 9
I had real poor mileage in cool weather, I blamed the winter diesel. Summer was better but still not great mileage. Turned out the
thermostat was broke. All the gauges show fine but the engine was not warming up well. I gained 2-mpg in town and can get
even better gains on long drives. Might be worth checking.
thermostat was broke. All the gauges show fine but the engine was not warming up well. I gained 2-mpg in town and can get
even better gains on long drives. Might be worth checking.
Ill have to check that. Never gave that one thought. My gauges show it running 190-195 deg or slightly more, the majority of the time. An easy check nonetheless
Thread Starter
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Tuned
Joined: Feb 2006
Posts: 354
Likes: 9
I know from towing for years that a strong headwind or tailwind can make a 2 mpg difference real easy,but thats pulling a fifth wheel trailer. Dont know what else to make that much difference. Make sure you dont have a brake sticking/ letting loose intermittantly- (slidepins).
Ive experiences the headwind / tailwind changes and expect such. I was also thinking about the brake calipers dragging too.
Thread Starter
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Tuned
Joined: Feb 2006
Posts: 354
Likes: 9
When I bought the truck, many yrs ago,, it came from a family member on a farm. I drove it 83 mph home for 150 or so miles on interstate (was in hurry because I had to go to work). Before I left I topped the fuel off at a local station. When I got home, it was topped off again. I got 19.2 out of it and 17 or so in town until I fueled it the third time. I suspect he had some premium off road diesel in it. (Whether that makes any difference or not) I even noticed a horrible drop when I put a K&N flat filter in it. That got removed real quick!
Im down to 1/4 tank and going to run it on down and drop the take to ensure I’ve completed the harpoon mod. At least remove that as an issue. Then off to the thermostat!
Im down to 1/4 tank and going to run it on down and drop the take to ensure I’ve completed the harpoon mod. At least remove that as an issue. Then off to the thermostat!
Laughing Gas
Joined: May 2007
Posts: 793
Likes: 29
Yes, slushbox is an automatic. Newer ones are not quite as deserving of that description, but the 4 speed mated to the 7.3 arguably does.
From the description of fueling method, this might play a part in inconsistent readings.
The fuel station might feed into inconsistent readings as well if it is an independent outfit sourcing fuel from multiple suppliers. If so, who knows what cetane or blend of bio is really in the tank. Am not bashing, just say-in.
For getting consistent fills toward calculations, consider taking some extra time to dribble fuel all the way to the filler neck where it is visible. This is not always easy as some pumps want to push a lot of fuel which in turn makes a lot of foam.
Toward the mileage, tires will make a noticeable difference. H/T's will get a good 10% better return compared to A/T's. Am definitely not looking to start a war on which one is better. Just stating the effect on the fuel burn.
From the description of fueling method, this might play a part in inconsistent readings.
The fuel station might feed into inconsistent readings as well if it is an independent outfit sourcing fuel from multiple suppliers. If so, who knows what cetane or blend of bio is really in the tank. Am not bashing, just say-in.
For getting consistent fills toward calculations, consider taking some extra time to dribble fuel all the way to the filler neck where it is visible. This is not always easy as some pumps want to push a lot of fuel which in turn makes a lot of foam.
Toward the mileage, tires will make a noticeable difference. H/T's will get a good 10% better return compared to A/T's. Am definitely not looking to start a war on which one is better. Just stating the effect on the fuel burn.
Thread Starter
|
Tuned
Joined: Feb 2006
Posts: 354
Likes: 9
Yes, slushbox is an automatic. Newer ones are not quite as deserving of that description, but the 4 speed mated to the 7.3 arguably does.
From the description of fueling method, this might play a part in inconsistent readings.
The fuel station might feed into inconsistent readings as well if it is an independent outfit sourcing fuel from multiple suppliers. If so, who knows what cetane or blend of bio is really in the tank. Am not bashing, just say-in.
For getting consistent fills toward calculations, consider taking some extra time to dribble fuel all the way to the filler neck where it is visible. This is not always easy as some pumps want to push a lot of fuel which in turn makes a lot of foam.
Toward the mileage, tires will make a noticeable difference. H/T's will get a good 10% better return compared to A/T's. Am definitely not looking to start a war on which one is better. Just stating the effect on the fuel burn.
From the description of fueling method, this might play a part in inconsistent readings.
The fuel station might feed into inconsistent readings as well if it is an independent outfit sourcing fuel from multiple suppliers. If so, who knows what cetane or blend of bio is really in the tank. Am not bashing, just say-in.
For getting consistent fills toward calculations, consider taking some extra time to dribble fuel all the way to the filler neck where it is visible. This is not always easy as some pumps want to push a lot of fuel which in turn makes a lot of foam.
Toward the mileage, tires will make a noticeable difference. H/T's will get a good 10% better return compared to A/T's. Am definitely not looking to start a war on which one is better. Just stating the effect on the fuel burn.
Dont disagree on what you’ve mentioned. Just seems old that the MPG’s seem to be all over the place. Just trying to narrow it down!