Fuel Milelage

[Me808garam]

Guys Im getting 20- 21 with SO 5 Speed 4. 10s 4x4 with 4500 miles on her. . Aloha from Hawaii

RonOo. Oo. Oo.

 

[PBeaudoin]

Originally posted by Maddey

I've been a little dissapointed with my fuel mileage. Ive got 3. 73s in a 4wd auto and have been averaging between 13 and 14 mpg. Towed the 5th wheel this past weekend and got around 10 mpg. Now I know this is not totally correct since I have 315/70/17s, but I had the same tires on my '01 with 3. 54s also and consistently got around 17 mpg. I am thinking about adding an edge ez to hopefully increase mileage a bit. Are there any other little tricks I can do to tweak the engine to gain better mileage.

:{ I am with you Maddey, I have the same rig exactly. I am getting 13-14 mpg on average. Very disappointed with it. When I first got my truck I was avg 16-17 on average. Hopefully you won't need a new transmission like me @6. 3k.

 

[bighammer]

My overhead readout seems pretty consistent with the actual numbers. I wish it had an instant fuel economy as well as average, because I kept resetting it to see what I was getting at that moment. Now that I've learned to leave it alone, and not reset it, It's really acurate.



With just 3300 on the odometer, mine's getting 19. 5 to 20 running around town. (combined with the to and from. ~7 miles each way)

 

[radar doctor]

Fuel Mileage

BIG HAMMER Please tell us about your truck?? 4X4 or 2 w Drive Rear End Ratio, Automatic or stick?? Tks Bill

 

[Rosco]

I have 1,700 miles on my truck and right now I am between 13. 5-14 MPG. most of my driving is the around town stop and go kind. My truck is a regular cab HO/48RE 4X4 with the 3. 73's. I have a cab protector attached to my E-Z Dumper so that adds some drag and I may still be getting leftover winter blend fuel so this may be affecting my mileage some.

 

[bighammer]

03 3500 SRW SLT Laramie Quad 4x4 LWB HO 6 speed w/BD Short Shifter 3. 73 LSD



A cut and paste from my sig. (went back to the truck info)

 

[jimnance]

Originally posted by Maddey

I've been a little dissapointed with my fuel mileage. Ive got 3. 73s in a 4wd auto and have been averaging between 13 and 14 mpg. Towed the 5th wheel this past weekend and got around 10 mpg. Now I know this is not totally correct since I have 315/70/17s, but I had the same tires on my '01 with 3. 54s also and consistently got around 17 mpg. I am thinking about adding an edge ez to hopefully increase mileage a bit. Are there any other little tricks I can do to tweak the engine to gain better mileage.

I'm getting closer to 9 MPG pulling my fifth wheel, but it is VERY heavy.



Yesterday, I calculated my around town mileage while not towing. This was calculated using actual fuel used and increasing the ODO miles by 9% to correct for the BFG 315's I have. The result was 17. 2 MPG. I live in a rural area, so true city driving would probably be lower. Interestingly, my highway driving is only running about 17-18 MPG as well. This probably has to do with my speed of 72 MPH.



My rig has the six speed so I don't know how that compares with the auto.

 

[Jeff Kelderman]

4x4 dually with 6 speed and 4. 10. drove it home from dealer oct 5. drove to from iowa to norman ok (to watch my beloved isu cyclones get waxed by the sooners in the rain) and got 11-12 driving 80mph.



still get around 13 average.



have not drove it enough to check since adding the bully dog box.

 

[jimnance]

Originally posted by Jeff Kelderman

4x4 dually with 6 speed and 4. 10. drove it home from dealer oct 5. drove to from iowa to norman ok (to watch my beloved isu cyclones get waxed by the sooners in the rain) and got 11-12 driving 80mph.



still get around 13 average.



have not drove it enough to check since adding the bully dog box.

4X4 Dually running 80 MPG suffers from three problems in order of importance:



1. Wind Drag. I forget the formula but the increase in horsepower required to overcome wind resistance increases almost exponentially. 80 MPH will be especially troublesome in a big truck with large flat plate section compared to a relatively sleek auto.



2. Rolling resistance. Two more tires rolling across the ground is going to hurt. Also, you have to spin the extra mass



3. Rear End Ratio. An engine turning more RPM's to generate the same speed will generally require more fuel.



It's very hard to get a good read on fuel economy because of varying driving habits and differing equipment.



What is certain is that our diesels will get far better fuel economy than a gasoline rig operating under the same conditions.



Also, keep in mind that these trucks have steadily gained weight. I think my '91 had an empty weight well under 6,000 lbs, while the new trucks with Quad Cab are well over 7,000 lbs. They also seem to stand taller which may hurt aerodynamics.

 

[jimnance]

Also, I think you'll find our Ford and Chevy diesel friends get no better fuel economy from a comparable rig. If anything they get poorer fuel economy.

 

[boonsur]

4100 miles and my average is pretty consistant at 15 mpg. Mostly empty at "slow" highway speeds (60-65).



I have a simple Excel spreadsheet to track. I print a paper copy with extra blanks to keep in the truck. I enter date/miles/gallons/etc. every time I fill-up (I always top it off). Just fill it out while waiting for the turbo to cool down, or while pumping. I'd be happy to e-mail it to anyone who wants it (send me a message).

 

[jimnance]

I'm surprised the Dual Wheels is hitting your mileage so hard. Except for towing I haven't had a tank less than 17 MPG actual measured fuel consumed/odometer miles.

 

[Jeff Kelderman]

my opinion is these new motors still dont get as good as milage as the previous motor 24v and the 24v doesn't get as good as milage as the 12v. we have 13 cummins dodges in our fleet. the best mpg we get are the older ones. granted they have more hp as they get newer.

 

[jimnance]

Originally posted by Jeff Kelderman

my opinion is these new motors still dont get as good as milage as the previous motor 24v and the 24v doesn't get as good as milage as the 12v. we have 13 cummins dodges in our fleet. the best mpg we get are the older ones. granted they have more hp as they get newer.

No Doubt. I had a '91 12V, a '95 12V, a 99 24 V, and now the'03 HO.



I think the reduced fuel economy is related to two things:



1. With more H. P. available you tend to use it consuming more fuel

2. The trucks have steadily gained weight over the years.



I'll bet if you put an '03 HO motor in a '95 frame and ran it on cruise control on flat ground you would get as comparable fuel economy to the stock '95.

 

[Russ99]

12,000 miles on my 03 3500 DRW 4X4 HO 6 Speed since 17 Oct. I've tracked all the miles with pen and paper. The mileage has been consistent at 17+/- commuting to and from work (approx. 12 miles). On highway trips I have gotten 18-20 mpg. Speed makes a BIG difference. Best mileage seems to be achieved at or below 2,000 RPM. I have towed about 6,000 lbs (full-size truck (Phord) on car hauler) a couple times. I got 14-15 towing this load at 65-75 miles per hour.



By the way; the onboard computer is very close, usually within +/- 1-2 tenths.



Truck is stock.



Russ

(Proud to be a USAF First Sergeant) I hit my 20-year mark April 15.

 

[The Frankster]

Russ,



Thank-you for your service!!!!!



Frankster



*My brother put 20 years in the Navy as an ASW--- Oo.

 

[ttreibel]

My Mileage

I have always tracked my mileage with pen and paper so her is all my averages since the truck came home on 12/15
17. 7
19. 6
16. 5
19. 7
11. 7 <--towing 7K TT
13. 2 <--towing 7K TT
13. 0 <--towing 7K TT
12. 8 <--towing 7K TT
18. 4
18. 5
17. 5
19. 4
14. 7<--mix Hwy & towing
19. 9
16. 9
19. 5
18. 4
18. 9
18. 8
19. 8
16. 7<--mix Hwy & towing
14 <--towing 7K TT
14 <--towing 7K TT
16. 4<--mix Hwy & towing
13. 1 <--towing 7K TT
13. 4 <--towing 7K TT
I am not the fastest truck on the road but I am also not the slowest the Ford 7. 3l NA this truck replaced usually got 11 pulling and 16 empty. I would love 30mpg ... maybe in the 5th gen cummins.....

 

[PBeaudoin]

I drove from Raleigh to Charlotte today and tried to stay at 65 MPH when I could. I am running 315-70-17's so that works out to 71-72 MPH when the speedo is at 65? The road hill hilly with some stop through towns here and there, I am getting 17. 8 MPG with the 9% increase added. I did notice that when I ran 60 MPH I started climbing some in the MPG area. very little though. I am happy with that. When I first got the truck on straight runs with no hills I got 21. 4 +/- with stock tires running 68-70 consistantly. The bigger tires definitely do not help at all. So, I am not complaining anymore!

 

[Maddey]

I posted earlier that I got an average of 10mpg towing my fifth wheel a couple weekends ago. Now, two tanks later, my average mileage empty has decreased to 10-11mpg. I called the dealer and am dropping the truck off this afternoon to hook it up to the computer. Hopefully, they will find something. I'll give an update when I get the truck back.

 

[Parshal]

I averaged around 17. 5 in town before I added the EZ. I was getting 18. 7 in town with the EZ. Last check at fillup before towing was 16. 78 though so I'm a bit worried something thas happened here. Before the EZ, I got 12. 5 towing my 3600 lbs. travel trailer at 70 mph. I just towed the trailer this weekend with the EZ and I got around 11 mpg at 70. Best was 13 and worst was 8. 5 mpg. I did add 1 1/2" blocks to the trailer to get it to level properly, though. I can't figure out how people are towing 10,000 lbs. trailers and getting over 13 mpg. It blows my mind when I look at the little thing I'm towing.