Crappy fuel economy? What gives?

[RaymondSmith]

Mr. Ketchum is correct. The other advantage in a gas rig is that the air / fuel mixture is kept at an optimum level through monitoring the ehaust gasses. To my knowledge, that is not done yet on a diesel rig.



Ray

 

[BBowers]

good point about the exhaust monitoring, I guess O2 sensors would make plenty of sense in a diesel, if they could be made with enough through pass to allow it to deal with occasional soot buildup. I wonder why this hasn't been done yet... I am however going to say that diesel and gas is not apples to oranges. Just because one is compression ignited and one spark doesn't change the laws of chemistry. More efficient monitoring and fuel delivery/control should have us seeing the same gains percentage wise that gas engines got when they went to EFI. I am incredulous about the NOX emissions controls actually causing more fuel burn, some sierra club hippie must have come up with that stroke of genius. I am sure with a lab i could prove that they cancel each other out, the increased fuel consumption offsets the NOX eliminated by simply making more reduced NOX level gas to compensate. Only thing is, it costs the consumer more fuel, drives prices up due to higher demand, drives engine purchase costs up for NOX defeating equipment, etc. Wow, how did we ever let our govt. get this far? Of course, carbon fiber bodies makes no sense, right? How bout fiberglass even? Lighter trucks get better mileage and have reduced emissions and perform better!

 

[Mr.Goat]

My 2003 has close to 98 K's on it now. I spent 9 weeks touring the west with the camper on it. Over 11 thou on this one trip alone. The engine seems to have more power, and definately gets higher milage than before this last trip. I think the engine is finally getting broken in. Mileage now sits around 20 -22 mpg depending on circumstances.

 

[DPKetchum]

Two VERY good friends with 03s BOTH exclaimed that at the 90k to 100k mark their fuel mileage is better then its ever been towing or solo. My airline pilot buddy drives his 03 bright red 2500 2wd auto 3. 73 like its a sports car. He KNOWS back roads and goes from the Athens area to all over parts of Tenn. and Kentucky by way of two lane,mountains etc. at 100k and on one of his trips he poped 23 mpg and HE will make you want a pass side grab handle above your head! He said DAMN this things just NOW broke in! Totaly stock STILL on the orignal brakes,one set of tries. Oil and filter at 7500 miles and 4 FUEL filters. service trans,diff and auto trans for THE FIRST TIME at 90k. Says BEST truck he's EVERY owned.

 

[spjohnson]

Load em down heavy and drive em like you stole em. Thats the only way to get them broke in.

 

[jcollier]

I have a 325/600 6 sp. 4x4 2500w/3. 73 40000miles on it. Stock CTD, I am getting on paper 21. 5 and 62 mph ant 65 it gets 20. The computer says about . 5 to . 75 more than paper... Oo.

 

[EConnelly]

When I first got my 03 I was getting 19 mpg. Now I have this obnactous knocking noise and I am getting 12 to 13. 5 mpg. I have had the truck in at 3 different Dodge 5 star service shops. I want a 10 star repair shop, one that can fix it. They tell me that is normal, some have better fuel milage than others. I tell them that with answers like that, you are not listening to me very well and that is why I hate my Dodge.

 

[Burner]

06 3500 4x4 CC here with 3k under it's belt. It's averaged about 11 so far. It pulled it's first semi-heavy load just this past weekend, I think around 18k. I got a whoop'n 8. 7 MPG on the 350 mile trip. I dropped the trailer and dead-headed home to the tune of 11. 7. I avg 62 'moving' MPH on the GPS going down and 72 on the way home. My fastest speed was 82MPH on the way home. I do hope it get's better, a lot better.



..... maybe a box will help it spike a little harder for break-in?







Burner



(My first post! )

 

[DPKetchum]

It will improve on its on. Just need miles and watch driving habits(speed)

 

[Burner]

Thanks, I hope so. I just don't remember having a Diesel get such poor fuel economy... even in the beginning.

 

[AMixon]

Oo. Well, I am glad I am not the only one feeling this way! My 2001. 5 was loud but man did it sip dino bones. Now my 2004. 5 gets mileage like my 440 in the Satellite, and the Dodge is nowwhere near as quick as the Plymouth! At this rate I would think the Mega Cab gets only 8 mpg... Maybe I can pick up on of these 'slighty used' M1A1 Abrams cheap... shipping is gonna kill me...

 

[ATofflemire]

I have a 2005 with 4K not much towing nothing over 10K got 22. 2MPG on the last tank running round empty city and high way driving. 3. 73 gears G56 trany, Rokktech sensor, no cat and aftermarket muffler. usaly get in the 19 - 22 range since the roKKTech instal.

 

[2Gen3Gen]

I have a 2005 with 4K not much towing nothing over 10K got 22. 2MPG on the last tank running round empty city and high way driving. 3. 73 gears G56 trany, Rokktech sensor, no cat and aftermarket muffler. usaly get in the 19 - 22 range since the roKKTech instal.

This must be a 2WD

 

[Mrudolph]

I get 19. 5mpg here in town, however I have no stopligts and only 2 stop signs to deal with on my way to work. On the hwy I get around 17 at 70 due to the lousy gearing on the G56. I need a US GEAR overdrive to get my RPM's down...

 

[ATofflemire]

This must be a 2WD

No mine is a 4 WD 4 door but most of my 40 mile commute is country non stop driving

All stock except the sensor and muffler

For now anyway

 

[Pourinthecoal]

My 05 Dually Auto with 5500kms is only getting around 12 MPG, up slightly from 11. 5 MPG off the hop. When I first got the thing, I drove it fairly hard unloaded, always making sure it was fully warmed up before getting on er. THen I loaded the truck down with 10,000 lbs (600 kms on it) and drove 800 kms as hard and fast as I could (85 MPH, couldn't go any faster, lotsa hills), with cool-down intervals every hour or two (idle for 1/2 hour). It didn't use any oil. However, lately I have not been able to work it, just driving around the farm for harvest, put 3500 kms and used a pile of oil, and mileage is still pathetic. I wonder if I should have drove it around easy for the first few thousand like the owner's manual says. Either that or I gotta put a load on it and get on er. Seat those rings. Whatcha guys think about this subject. Could I haver hurt anything by drving it so hard off the hop (always 2500-2800 RPM pulling)?

 

[FJfonda]

I have 29K on my 04. 5 and I get 13-15mpg unloaded and 8mpg pulling 12K lb boat/trailer. This has been the same since new and the variation has more to do with winterized fuel than anything else.

I'm not really happy but the truck drives real nice.....



The only thing in the driveway that sucks more petrol is the boat at 1. 4 mpg.

 

[JThiessen]

I've now got 50K on my '03 and I'm going backwards... now at 14. 7. Used to ave. around 16 stock, then up to 17. 5 after mods, including switching over to Royal Purple and Amsoil in the drivetrain. If I used my overhead as it seems a lot of people here do now, I would be reporting the opposite - both due to its own inherent error percentage, and the fooling the XZ does.

I tow, and have since new (10K lbs). I run it fairly hard when towing, and fairly mild to average when empty. My theory on the "break it in for better mileage" is that its a wives tale, and probably has more to do with other factors than "break in".

But what I hope for most is that they will get rid of the @&$&^ Overhead MPG... .

Not to be too smart or anything, but I just stopped used the SP Diesel Elminator box on my '05 and am now beta testing (again) their newest box. Just going by the overhead. 14. 1 MPG on the old 16. 5 on the new City driving. For the first time, just after the install at Fall Brawl on the way home I got 20. 7 MPG on High Output (HO Mode) and I'll swear thats the highest I've ever seen on the overhead. Now remember, this is the first tank of fuel with the new box, and I haven't had time to hand cacl everything, but it sure looks good from here. SP Diesel ( http://www.spdiesel.com/ ) is really working on things our trucks are looking for. Heck They even solved my old P0111 code problem and allowed me to start using my CB Amp again. I'm a BETA tester for them am I'm really looking forward to what they plan to give me and the production boxes. (BTW Just between you, me and the fence post, They have several features you will NOT find elsewhere. )

When I first put my EZ on back in '03, my OH showed an increase of 2. 8 mpg Oo. But a simple calculation showed only . 4 increase Prior to installing the EZ, the OH was only off by about . 3 to . 5 mpg.

 

[Burner]

... So, how much advance is needed for better returns?

 

[jackcaptjr]

I agree..... The CTD is a medium duty diesel in a lite duty PU. Just towing 15K 10% of the time does not qualify as hard towing. These things are made to work hard and that assumes hotter and higher cylinder pressures than most of us load it to. I'm about 50% of my miles with 15K or greater behind the rig and pulling some serious grades. With 25K on it the mileage is just now starting to improve. Started at less than 15 and is now up to 17+ on average hi-way tank. Old 99 continued to improve it's entire life. Sold at 110K and 19+ on the hi-way... ... . most likely just broken in... ... ... . I'm talking ring seating and drag.