My 04.5 is only getting 14.1 mpg unloaded with about 50/50 mix of highway and city driving. I just filled up tonight and hand calculated the 14.1, my overhead reads exactly the same. I don't beat on my truck, I think I drive it pretty conservatively, the most load it sees is two dirt bikes with all riding gear and tools etc. Is this something I should be worried about? The truck has 13,400 miles on it, a relatively new fuel filter, and new oil and filter. The oil didn't smell like fuel and wasn't overfull. The truck is calibrated for the 285's, I even checked it with my GPS. I don't know what to think. Any help is appreciated.

 

I would have to say that you're not too far off on your mileage figures.. especially if you're running winter fuel right now and your 50/50 mix of driving. Right now I drive about 8 miles to work (one way all highway).. been seeing about 15 hand calc. btw.. my truck has 20K on it right now. I did not see if your truck was auto. or 6-speed in your sig??? also 3.73 or 4.10's??

 

I wouldnt worry about mileage for the first 20000 miles, especially if the truck has never been worked. Just put your foot to the floor as much as possible. Get it hot, then milage will eventually get better.

 

Mine is still improving with 54,000 on the ticker. I just hand calculated 16 mpg, combo city/highway on my last tank. If I would slow down on the highway im sure it would improve by at least another mpg or more.

I believe the break-in on these engines takes quite a while.

Also, I added a Smarty programmer about 2-3 months ago and that seems to help my mileage some too.

 

Thanks for the replies guys, I guess I'm just a little paranoid. My truck is an auto with 3.73's, sorry for not including that. It sounds like I've been too nice to it, maybe I should go beat on it a little bit. Thanks again.

 

have you had any of the newer flashes, or is it the original from the factory? and where in washington? if you are close by, we can get you a heavy trailer 10K and have you run around with it for a while to get her done right.
chris

 

I regularly see 18+mpg on my 04.5 in 50/50 combination driving. My truck has just over 50k on it and it's been towing since it left the dealership lot. That's what most of you all are missing IMHO!!! These motors are designed to work. They don't get broke in right unless you're hauling something.

 

My experience has been that (I know you guy's are gonna hate me) most of the people that get (or at least post) the 18-24mpg in the 3rd gens must:
a) Drive VERY SLOWLY....
b) Don't haul anything....
c) Trust their on board comps....
d) have faulty calculators/fat fingers??
e) and live far from stop lights and traffic.

All the CTD's i've owned have got around 12-15mpg, in fact the best tank I can remeber was on a recent trip I took to cabbo san lucas, baja in the 06 which was a little over 17mpg burning mexican SHSD (super high sulfer...yeh I made that up, but the fuel there in mex must be better than what we use here) and I was driving between 45-60mph, no stopping, no traffic, light load (camping junk/surfboards) for about 500mi (90-120kph).

Anyway just be happy that you have enough power to get bad gas milage.

 

i would expect you to get better than that. I can get about 20 with my truck i know its a 2000 but its a 1 ton drw 4x4 5spd. If i were you I would check my tire pressure at low speeds tire pressure and wear are more responsible for fuel mileage than aerodynamics. I don't know how far your drive is but if i stay on the highway unloaded going 65 at most and that is hard to do but if i stay under 65 i can get 19-20 consistently.

 

As others have said already, Ya gotta work these beasts!! I bought my truck for work, towing, and when it was brand new up to about 5k it only got 9 m.p.g. loaded or empty, driving fast or slow, it didn't matter. I thought I was going to lose my butt with that kind of fuel mileage.
Mileage improved with age and use. Today, with 285k on the clock, it gets between 19 & 20 m.p.g. @ 75 m.p.h. empty and between 12 to 15 m.p.g. towing trailers around 12k lbs. @ 75 m.p.h. depending on fuel, wind & terrain.
Oh, I forgot, haven't had a tailgate for a while either. I'm sure that helps alot.

 

Driving 65 mph i'll get 20 - 21 mpg....but as soon as i go over 65 mph i'll get about 15 mpg. Since most of my driving is between 70 mph & 90 mph i'll only get 13 mpg average....450 miles on a 35 gallon tank. My Cummins has 13K miles on it. I wish tho i would be getting the same milage with it as the D-Max gets.

 

I get about 14 around town and 20-22 highway hand calc..... I did the tone ring mod, switched to synthetic engine oil after 15K miles, swiss cheezed my air box, and the hardest part.....Drive EASY

The first thing you need to do is put some miles on it, It's not even broken in. Borrow a trailer with some weight, 7,ooolbs or more and drag it around a while. That will help seat everything. You NEED to work that diesel a little. Then switch over to synthetic oil (I picked up better then 1.5mpg) and do a search for the "Tone ring mod" (Added about 1-2 MPG around town). Real easy to do in less then an hour. Drill some holes in the bottom of your airbox to help it breath.

Also, as mentioned above, make sure you have the latest re-flash. That was a big improvement. Good luck.....

 

you guys are getting great milage compared to what i have been getting. i have been averaging about 10mpg while pulling about 15-17k every day since it was new.i use amsoil products and i dont have a chip in my truck.the best i have seen was 16mpg while not towing.

 

Mine is a 2005 4x4 with 7000 miles around town, the mileage is acceptable at about 15, much better than what I was getting with my 1986 chevy k20 with a 350 and automatic at about 8

on the HWY, this truck does much better, my weekly commute is 500 miles, the morning I average about 70 mph with no traffic, the afternoon has more traffic, so speed never gets above 55, weekly the truck is using 24 gallons for the 500 miles, and each morning includes over an hour of idling since I get to work so early, and cant sleep in a cold truck
I run unloaded and easy with it, fill it till it wont take any more not sure of the gearing, but it turns 2000 at 70mph with 265/70-17 tires inflated to 70 lbs

 

My truck is supposed to have the most current flashes. When I was in Iraq my truck was in Iowa and I had my dad take it to Woodhouse in Blair, NE to get everything current and get the high idle activated. Well somewhere during the reflash the ecm locked up and didn't respond to anything and they replaced it with a new one that was supposed to have the current flashes. Needless to say I didn't get my high idle until I got out to WA. How do I check for the current flashes? There is only one TSB tag on the core support and that is for the belt chirp after it shredded the belt at 13000. I am now in Olympia, WA and the only trailer I have is a little single axle 4X8 I use for the bike occasionally. My overhead is slowly going up and when I calculated it last time it was right on so who knows, now it reads 14.2. I realize these trucks like to work, but I bought mine to maybe work every now and then, and up until it is time to work it is my daily driver. Thanks for the replies guys.