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I am only getting 12 mpg at 75-80 mph with my truck. I have a 50 mile commute everyday and that is what I am getting. It has 2500 miles on it and I just had it into the dealership complaining about it. There diesel tech hooked up to it and said everything looked good. It seems to run good. The engine fan seems to be engaged alot when I take off from a stop light or even when it is cold sitting there idling(you can hear the roar). Any ideas?
 

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TRY RESETTING THE D.I.C. THATS LOW (NO TOWING?) I'M GETN 17 SOME HIWAY, SOME CITY. ARE YOU GETTING THAT READING OFF OF THE TRUCK?, OR ARE YOU FIGURING IT AT THE PUMP?


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Engine fan should not be enaged as much as yours.The fan on mine will enage for less than a mile when cold and then it is done,thick oil in clutch must make it stick.It does not even do that on all cold starts.The only time I hear the fan with a warmed up engine is when pulling my fifthwheel and then only when pulling hard.I would suspect when the fan is enaged that fuel consumption would increase somewhat.
 

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Although I have the LLY, our trucks/tires are nearly identical. My daily commute is 46 miles roundtrip. I have not noticed the fan, but my mileage is 14 mpg. Not very good, either. I get on'er now and then, but drive fairly easy most of the time. My torsion bars are cranked 1.25". I am hoping that when the winter blend goes bye-bye and as she breaks in, the mileage will increase.
 

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I also have the LLY and my first two tanks were 16.0 & 16.2 with some warm up time, this was mostly secondary roads & some highway. My last tank was 14.2 with all secondary roads and no warm up time at all. I have noticed that my clutch fan is engaged while it is cold also first thing, but also that the transmission is holding the gears longer & that it won't shift into fifth gear until about 8-10 miles down the road depending on outside temperatures ( I do realize this is a function of the truck to help warm it quicker). I also am wondering if my fuel supplier is trying to get rid of his winter-blend fuel as this last tank was the easiest I had driven the truck to see what type of mileage I could get ( I have always used the same supplier for fuel at this point along with stanadyne fuel additive). Hopefully my mileage will improve with the temperatures increasing some time soon. I am planning a trip to South Carolina in two weeks & I will see what I get on a trip and post it then. I have done all my fuel calculations by hand and record them all.


Fran
 

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I have a lb7 2004. Getting 15 most of the time... I also commute 45 miles of highway each way to and from work. It kinda sucks really I traded in a 2002 lb7 and got 18 to 20 all the time.


Let me know if you figure out anything. I would like to get back to at least 18. Its supposed to be the same truck. I don't know what changed?
 

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I have the 2004 LB7 and I run back and forth about 100 miles daily, been getting 17.8-19.5 running with cruise set at 75.
 

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My 04 LB7 got 17 mpg on the first couple of tanks with the 245s - this was in the south with warmer temps. The last few fills are averaging about 15.5 mpg and that is on the 285s with Predator. That has been in colder weather. I am patiently waiting for warmer weather.
 

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Discussion Starter #9
sky1 said:
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TRY RESETTING THE D.I.C. THATS LOW (NO TOWING?) I'M GETN 17 SOME HIWAY, SOME CITY. ARE YOU GETTING THAT READING OFF OF THE TRUCK?, OR ARE YOU FIGURING IT AT THE PUMP?


How do you reset the D.I.C. That is figuring at the pump. All highway miles. </TD></TR>
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I get 15 or 14.7 during the cold (below +30 deg) months. I believe this is mostly due to the tranny not coming up to temp for a while. when it above 30 my milage will range anywhere from 16 to 19. for a 1 ton 4x I can live with that. thought about putting on one of those oil pan warmers on the tranny for cold weather. any idea's fella's??? Bill Edited by: AkDually61
 

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I'm getting anywhere from 17.5 to 19.5 in TN. (This is for the first 5k miles, which is all the truck has on it.) That's a mix of windy two lane country roads and freeway and 50-75 mph.
 

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coacholy,


I noticed you are in a very cold part of the country right now, and although things are warming up it is still cold. Are you sure your truck is warming up? (not meant to be funny) These trucks have grill shields that will help them warm up in cold temps. The fact that you hear the fan as oftem as you say, tells me that your truck in fact might not be fully warming up. Look into the shields, they are cheap.


Bill
 

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Discussion Starter #13
Redapple said:
coacholy,


I noticed you are in a very cold part of the country right now, and although things are warming up it is still cold. Are you sure your truck is warming up? (not meant to be funny) These trucks have grill shields that will help them warm up in cold temps. The fact that you hear the fan as oftem as you say, tells me that your truck in fact might not be fully warming up. Look into the shields, they are cheap.


Bill

Up here were it is cold, my truck came with a cold front which covers the grill and bumper. At 30-40degrees, I am still getting 12mpg. It hasn't been warmer than that since I got the truck.
 

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2004cc sb 2wd, 19 combo driving trip to myrtle beach 21.7. I have a light foot around town but will run 75 on the interstates. I am pleased.
 

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The winter fuel you have this time of year in ND is worth about 2 mpg loss. Our trucks do not have the greatest aerodynamic form, and 75-80 will be significantly worse mileage than 65-70.


My truck got poor mileage (16 on the freeway in the summer at 65-70) until around 5000, then it picked up to about 14 in town and 18-20 on the freeway. That slowly improved to about 14.5 in town and 20 on the freeway. At 18K my truck made another improvement in freeway mileage. Nowadays--with 23K--I get about 14.7 in town and 20-22 on the frewway at 65-70 mph. I have the 125 HP Juice set on 5/5 and 285 75R16 tires.


I think that when you get out of the winter fuel, get some more miles on your truck, and keep it around 70 mph max your mileage will significantly improve.


Blaine
 

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Could it be that the high idle warm up mode is affecting LLY mileage adversely?
 

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22 MPG @ 65mph, tailgate down, me and the wife and the dog in it.


17-18 @75-80. talgate up, same load


2004 CC/SB LB7 4x4.


Can't wait to see what sort of a difference the bed cap will have.
 

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I drive 10 miles hwy one way to work with 2-3 miles city total 22 miles a day last fill up 16mpg but my top speed is 60.. Took a trip last Dec to FL 20- 21 mpg at 65-70mph.. I ride In the right lane and cruise whenever I can. Enjoy the ride.
 
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