9.5mpg towing, 14.5 empty...OK or prob?

[TShores]

Hey gang,



04. 5 2500 4x4, auto, 3. 73 with camper shell and lumbar racks. 17k miles. The current fuel prices have me paying closer attention to mpg. I'm consistently getting 14. 5 empty, in mostly highway, some rural town roads. Feels OK. I have a light foot. I have 33's BFG AT's with the speedo corrected.



But towing a 7500lbs travel trailer is dropping me down to 9. 5mpg. It's a big trailer 30', but are you guys with Fifth wheels getting about the same?



I've had the mileage flash done. But still get some white smoke at start up, and just recently noticing pretty rough starts when cold (could be called "misses") until I up the idle (using high idle).



Mileages are both hand and overhead calculated (amazingly accurate in my case).



Start looking at injectors, or everything within spec?

 

[PJ]

The dealer told me it was normal. . Every post I seem to make regarding this, the replies I get state its normal, yet there are those guys that still claim to be getting 28 mpg on the highway and 20 towing. . I doubt they can add and subtract. . I would say that your stats are about 2 or 3 mpg low, but trying to get the dealer to address the problem is a problem in itself. . Good luck. Welcome to the 50 state legal CTD. . My 04 305-555 HO got alot better mileage than my new one and never smoked. . Gotta love all the emission controls! :{

 

[RJOL]

Really no way of knowing the type of terrain your driving over but if most of your highway miles are on relatively level ground, I'd say you are at least 2-3 MPG under what you should be seeing. Could be a result of the weight and drag you have with a camper shell and racks on.



Are you sure your odometer is correct with the 33's? Have you checked it against a GPS or highway speedometer test areas? Just cause somebody corrected it doesn't mean it is right.



I live in NW Washington. Most of my driving is without my trailer. I routinely got 17-18MPG highway, and 14-15 city. This is with a 5 speed manual, but with 4:10 axles. Towing my 11K 5th wheel I usually got between 9-12MPG towing at 65-70MPH on the freeway. Differences in MPG between similar trucks has always been a mystery on the TDR...

 

[TShores]

Yep,



I have tested the mileage correction both with Mileage markers and Speedo tests (and GPS). It is spot on. Terrain is mostly highway (I5 in Oregon and California). Also mixed rural small roads.



I agree with the 2-3 mpg low statement. I wonder if it just the combo of Lumbar Racks, Shell, and bigger tires.



T

 

[daytripper63]

diesel fuel is getting all the good stuff (sulfer-cetane-etc) refined to lower levels to reduce emissions and when this is done it also reduces mileage I have dropped mileage on my truck as well.

P. S. got info from a fellow Cummins owner whom works for refinery, he also claims all the extra work to diesel fuel is reeason it is more $ than gas

 

[DPKetchum]

Towing about 8600 lbs extra tall 3 horse steel horse trailer(gooesneck) etc. I reset my ovehead several times going from Athen's Ga to Charlotte N. C. and back. It settled in to 11. 4 every time and I never went over 68 mph but brielfy down hill once or twice. Its was rolling hiway,defrost on and steady rain. temps were in the low fortys.

 

[DPhillips]

Just got back from McComb,Ms. pulled my 6x12 cargo trailer there(empty) and back(full). Keeping a light foot on the pedal I got 13. 4mpg(going) and keeping a light foot(below 2000rpm) I got 12. 9mpg(back). I have 16,000 miles on the truck, no flash for white smoke because I haven't seen any. Go to the "Pay It Forward" section of the TDR and get the Excel program provided by one of the other great members and it will help you keep track of your mpg, service cost etc. The worst mpg's I got was pulling my 5er to Illinois at Thanksgiving (8. 6) I was using my heavy foot on the go pedal on that paticular stretch of hi-way and fighting a serious head wind. The best empty mpg was 16. 2mpg just driving around with a light foot mixed city/hi-way.

Hope this helps

 

[Posm]

I am seeing simular mileage loaded, but better mileage unloaded. I drive about 60K per year with many different type of loads. I pull a 7000 LB hay baler at 70MPH that is nearly 10 feet tall and blunt shaped. It will put mileage down under 10MPG. I can also pull a loaded goose that weights over 14K and gets about 12 MPG. The wind resistance is everything. I have tried to find if RPM make a difference and can not tell that it makes much change in MPG. I do this by running at a set speed in 5th instead of 6th gear. If you try to increase the RPMs the same amount in 6th gear the mileage drops like a rock. I see 3MPG less at 75 than at 65MPH.

I had a 2000 that I put 200K miles on in 3 1/2 years. It would get 1 to 2MPG less unloaded and 1 to 2 MPG more loaded than my 2004 will. The 2000 had a 3. 54 and the 2004 has a 4. 10.

 

[RTuvell]

diesel fuel is getting all the good stuff (sulfer-cetane-etc) refined to lower levels to reduce emissions and when this is done it also reduces mileage I have dropped mileage on my truck as well.

Do you have any basis or direct knowledge to substantiate your claim that "when the refining to reduce emissions is done it also reduces mileage"?



I am aware that the refineries are under government mandates to produce cleaner diesel fuel especially to lower sulfur content. I am also aware that some folks claim that this additional fuel clean-up has an adverse impact on the lubrication properties of diesel fuel. But your's is the first claim I have ever read that the refineries are "refining cetane to lower levels" and "when the refining is done it also reduces mileage.



My questions here are specific to the diesel fuel itself. I am well aware of the MPG issues that have been reported about the 04. 5 and later trucks.

 

[LightmanE300]

Do you have any basis or direct knowledge to substantiate your claim that "when the refining to reduce emissions is done it also reduces mileage"?



I am aware that the refineries are under government mandates to produce cleaner diesel fuel especially to lower sulfur content. I am also aware that some folks claim that this additional fuel clean-up has an adverse impact on the lubrication properties of diesel fuel. But your's is the first claim I have ever read that the refineries are "refining cetane to lower levels" and "when the refining is done it also reduces mileage.



My questions here are specific to the diesel fuel itself. I am well aware of the MPG issues that have been reported about the 04. 5 and later trucks.

His comments were purely speculative in my opinion. Either that, or he's run off road fuel/HS diesel in the past and enjoyed the mpg benefits of the slightly higher BTU's of that particular fuel. The ULSD/15ppm fuel that's been discussed a lot recently isn't coming out for a while. The current LSD (low sulfur diesel, don't get excited hippies! :-laf ) that's available hasn't changed in some years.



The refining process that removes sulfur from fuel also strips some of the fuel's lubricity. Lubricity enhancing additization occurs at the refinery, and some addtionally at the pipeline terminals when fuel is separated and branded. Right now lubricity isn't a huge problem, but as ULSD is introduced, it will be more of an issue. You will see a lot more people using their own additional lubricity additives, dumping who knows what kind of lame brained vegetable oil, and other things in their tanks.

 

[WStoops]

These posts are really interesting. I tow 8500 lb loader/backhoe/trailer. The whole package is not real high, in fact, barely higher than my truck with the hi-rise Jeraco Cap. I get 14. 5 to 15 towing that, depending on terrain. Unloaded, I have been getting 16. 7 around country town (no lights or traffic) and 20. 5 highway at 65 mph. Faster than that and the drone and vibes make me crazy. Wind resistance may be a more significant factor than weight. (as you double speed, wind resistance becomes 4 times greater) Last summer I drove mine on a long trip and discovered, as many others have said, that as the speed goes up past 70, the fuel consumption goes off the chart. All hand calculated and I can divide, add and subtract.

 

[RKerner]

Mileage woes

I get 9. 5 -9. 7 mpg towing 7500lbs at 65mph when the temp is less than -10F. I get 10. 4-10. 8mpg with the same load at 65mph when the temp is between 20F and 45F. I've lost mileage since the reflash, especially unloaded combined mileage. This is all using the same blended fuel from the same station. This is both with and without Edge Juice/Attitude and driving with a light foot. So far, I'm thinking that this combination should do better or maybe a guy should start looking at an '05... .

 

[RTuvell]

I get 9. 5 -9. 7 mpg towing 7500lbs at 65mph when the temp is less than -10F. I get 10. 4-10. 8mpg with the same load at 65mph when the temp is between 20F and 45F. I've lost mileage since the reflash, especially unloaded combined mileage. This is all using the same blended fuel from the same station. This is both with and without Edge Juice/Attitude and driving with a light foot. So far, I'm thinking that this combination should do better or maybe a guy should start looking at an '05... .

From what I've read the MPG issues started in 04. 5 and have continued into 05, so there is no reason to expect an MPG improvement in an 05.

 

[DPKetchum]

Can some of you nice folkes include gear ratios in your sigs. 3. 73 or 4. 10 etc.

 

[tractorseller]

05 3500 DRW quad cab 4X4 with 3,800 miles on it, mostly pulling tractors, trailer stacks, and empty trailers. I'm averaging 14. 5 mpg with 3. 73 gears and a 6 speed. I run between 65 and 75 mph.



I'm not complaining about my mileage. It's very comparable to what my Chev 3/4 ton Duramax got, but this Dodge is a heavier truck and is pushing more wind with a higher profile. Runs like a dream. No smoke at startup either. I might point out that my engine is the "old" 600, not the newer "610".

 

[Po' Riggity]

I get about 19-21 mpg highway, empty in my CTD600, 6 spd 4x4 quad cab long bed 2500.

Scott

 

[10.5 Dave]

I just made a 3,000 mile round trip to Florida last week. Running 75-80 mph empty the best I could do was 13. 7mpg. These engines get really thirsty above 70 mph.



In Nov I made a 2200 mile trip at 22,600 lb gross with my 44' gooseneck toy hauler. Went from Columbus to Baton Rouge at 75-80 mph and only got 8. 3 mpg. From Cincinnati-Jackson Miss I met every hill with however much throttle it took to maintain speed.



The truck would probably get 12 mpg at 65 mph pulling the trailer.



I get my best mileage in mixed city/highway driving. If I shift at less than 2k I can get 17. 5 mpg.

 

[Scooby]

Wind resistance is everything....

I was on the highway yesterday and did a little experiment.

On flat ground I got close to a semi's tail and drafted behind him with my cruise control set. I Reset the overhead computer and saw 24. 3 mpg for a little while. Then I got out from behind the tractor trailer and reset the overhead computer (while keeping the cruise set at the same speed) and the mileage dropped to 16. 7 I think we were running around 70mph.



I've got 7500 miles on the odometer (bone stock). I have been doing very little long distance driving so most is mixed, with mostly city driving. My best is 16. 2 mpg so far (empty).

 

[DPKetchum]

Does not towing at that speed and weight not seem safe. 70 is my limit period towing and usually not that.

 

[Rodzilla]

white smoke is usualy not getting enough fuel i would have an overhead done and posssibly change the fuel filter