Just wondering if anyone else is get this mileage. Truck was running without a load or not pulling anything, just normal highway driving average speed of about 75 mph on open highway and speed limit around town. Had truck fuel tank drained before due to bad fuel and puffing white smoke real bad. dealer reprogramed it and charged an arm and a leg. After that issue was cleared, the turck got this mileage. Before, my average was about 17-19 miles a gallon driving off the lot. By the way only have 2100 miles on it. Thinking of switching back to a gasser, one mile difference between the two. help.

You shouldnt have had to pay a thing. Its under warranty.

Ive got an LB7, averages around 19 mpg, highway and town mixed................12 mpg and somethings wrong.

Ide give it a few more break in miles before you make a move.

Just wondering if anyone else is get this mileage. Truck was running without a load or not pulling anything, just normal highway driving average speed of about 75 mph on open highway and speed limit around town. Had truck fuel tank drained before due to bad fuel and puffing white smoke real bad. dealer reprogramed it and charged an arm and a leg. After that issue was cleared, the turck got this mileage. Before, my average was about 17-19 miles a gallon driving off the lot. By the way only have 2100 miles on it. Thinking of switching back to a gasser, one mile difference between the two. help.
With only 2100 miles on your truck, don't expect good fuel mileage. YET.....
Not only is your engine tight, but so is the tranny, and every bearing and seal involved in the whole drivetrain assembly. Give your vehicle a chance to break in, but be prepared for it to take awhile. Keep in mind a gasser will be similiar when new, too, however the break-in period is less in a gasser. But so is the power, the longevity, the re-sale, and the mileage in the long run.

I've got just about 2,000 miles on my '05, and I averaged just a tad under 16 MPG on a weekend trip to West Yellowstone. That was with warm up times in the mornings, driving in rain and snow, at higher elevations, and at sustained speeds of 80 MPH on the return trip home. A gasoline 2500 HD 4x4 wouldn't do that with similiar miles on it, I'm sure.

Its not even broken in yet......

I got (consistent) 20 mpg highway with less than 1000 miles on mine (Denver to CA)................Maybe the autos are different........

I got (consistent) 20 mpg highway with less than 1000 miles on mine (Denver to CA)................Maybe the autos are different........
Speed, weather, temps, tires, etc., all play a HUGE part in the mileage game.

Speed, weather, temps, tires, etc., all play a HUGE part in the mileage game.

don't forget "weight of foot.." LOL

you can search for posts on mileage and find tons...its been hammered to death. The LLY's seem to start off with over 15mpg, then drop to 12 then creep back up and over with every tank. I went through this on mine as well. I am now back at 15mpg city and climbing.

if you go back to a gasser you will regret that my friend, just my opinion, but once gas prices go back down you will be wishing you still had the diesel, not to mention when you try and tow something.

give it time, it will break in.

well I get 99MPG, according to my D.I.C.....when I'm coasting. ;)

actually I'm probably averaging 14-16 MPG on average and drive it pretty hard.

You said you were getting much better mileage, then got a bad batch of fuel and now the mileage is down?

Do you know where you got the bad fuel? They probably should have paid the bill. You might still be able to hold them accountable.

Did the stealer change your fuel filter when they cleaned up the rest of the mess? Regardless, is it clean now or did some of the contaminants collect in it? Maybe run a tank or two through this filter and then put a new one on.

I get 14-15 pure street driving it delivering pizzas, thats with my xcelerator full blast and 315's. it did go down to 12 and 13 for about a week, then its going back up where i got 14 and climbing. best i have ever done on pure highway test going 60 mph was 29.6. i only traveled from san diego to vista on that test.

Mine was upper 12's new. It is at 18.8 according to the DIC now with almost 16000 miles on her. I was getting 19.8 coming back from Laramie, WY. Give it some time and try filling up at other places. My mpg's take a 2mpg hit when I fuel up at this one Exxon place and at another, it gets higher. Should be the same fuel though...

Highway mileage should not be 12mpg unladen. 15? Perhaps. 12? Nope. Something is either wrong with the calculation or the truck. Normal highway mileage unladen is 16-21 depending on your truck.

You shouldnt have had to pay a thing. Its under warranty.

I don't think they will warranty bad fuel. I was getting about 13mpg, and just started to see 15-17 now with 5,500k on it.

my 05 was getting 12.5 last week( walmart fuel station) after an avg of 16-17 in the city, so I switched to shell diesel and I'm back to 16. I think my problem was just bad diesel !!

funny... I have used shell since I purchased the truck new. I was getting 13 in the city. I switched to Chevron and the first tank I got 15

With only 2100 miles on your truck, don't expect good fuel mileage. YET.....
Not only is your engine tight, but so is the tranny, and every bearing and seal involved in the whole drivetrain assembly. Give your vehicle a chance to break in, but be prepared for it to take awhile. Keep in mind a gasser will be similiar when new, too, however the break-in period is less in a gasser. But so is the power, the longevity, the re-sale, and the mileage in the long run.

I've got just about 2,000 miles on my '05, and I averaged just a tad under 16 MPG on a weekend trip to West Yellowstone. That was with warm up times in the mornings, driving in rain and snow, at higher elevations, and at sustained speeds of 80 MPH on the return trip home. A gasoline 2500 HD 4x4 wouldn't do that with similiar miles on it, I'm sure.How much longer do I need to wait. I have over 60,000 on one and over 100,000 on the other. If we get 15mpg MT I feel lucky. Both have been to the dealer for it, but they say no specs have ever been posted by them on mileage, so mine is OK.

I feel your pain. My '04 LB7 started out at about 12, and as I got closer to 10K on the clock, was about 15.5mpg empty and almost 12 towing, according to DIC. It started to throw raw fuel when towing, so took it to the dealer. They replaced MAF sensor, which cured the throwing fuel problem, but mileage instantly dropped back to about 12.5mpg. I now have over 18K on the clock and it is still at 12.5 empty, according to DIC. Dealer says all flow rates are normal, no codes, etc. Also says that if ANYTHING hickups on the engine controls, a code gets set. Wish I had just kept cleaning up the mess of fuel in the bed and off the front of my 5th wheel. I'd still be getting 15.5 or better. Wierd thing is that I don't loose that much when towing at 18,000 GVW. Only drops to about 10.5mpg.

thanks for the advice, I'll give it a copy of more miles. Yes they did change the filter when they drained the tank and dealer told me warranty did not cover draining the fuel tank. Taking gas station to court for selling me bad fuel, to try and recover my expense for the repair. Again thanks for the advice.

Picked up my first diesel vehicle in September, brand new LLY. Joined this forum and was told a few things from Nick and others that I've followed. (currently have 18K miles on it.)

1. Log fuel purchases, mileage, etc and save all receipts from purchases. (I bought a small notebook and a small travel file folder - keep it in my truck - save receipts with it and they are numbered to the log entries). Someone recommended I do this to make warranty easier and to document/log where i purchased fuel in case of such an issue as this. Some companies (BP, Shell, etc) may warrant their fuel, but you would need this sort of documentation.
2. I have found through this log, that MPG will VARY greatly based on how i drive, outside temperature and where i got the fuel. Anywhere from 12-19mpg... most common is about 15-16mpg. This log also allows me to hand calculate to compare to DIC with each tank. I'm in a stock truck and I have found the DIC to be accurate if you reset the FU/MPG settings with each tank. (makes sense to not average.)

3. I think most guys are exaggerating about consistently getting 19-20mpg...i've seen it on trip or two - but it's not very common - and NEVER when i'm doing 70-75mpg.
4. I have found Bio-Diesel (purchased twice from a Kwik Trip near Wi Dells) to give me reduced mileage regardless of driving conditions.

5. I also note in the log any reimbursable miles for work - any maintenance items done and any odd behaviors noticed. (noises in the truck, starting or running patterns, etc) So I have accurate logging of all this.

6. I followed Kennedy's recommendation and keep a spare fuel filter and wrench in the truck. I also have to keep a socket for removing the left battery - as I am not talented enough to swap the fuel filter with the battery in the truck - just not enough room for me.

7. When I'm not on the road, i make a concentrated effort to get fuel from the same place. When I am on the road, I pick a place that will turn the fuel around (truck stop, etc.). If I have not choice and am not sure of the station - i put in only enough to get me to the next station.

Might seem like a hassle, but it's not nearly as much of one as getting a tank full of junk fuel. Won't guarantee is doesn't happen to me either - but I think they were good recomendations. Thanks Nick and JK.

Now I just need to add a pre-oem fuel filter to my truck...

my dad gets a constant 12 up to maybe 16 in the summer on his lb7 and he runs well lets say it is the same stuff we run offroad.

Highway mileage should not be 12mpg unladen. 15? Perhaps. 12? Nope. Something is either wrong with the calculation or the truck. Normal highway mileage unladen is 16-21 depending on your truck.

Agree with McRat - got 35k on my lly and it has always gotten 16-22 highway and 13-14 towing unless bad fuel then less, agree with changing fuel filter. Also can see a real difference in mpg when heavy with foot and when i stay under 2100 rpm's great mileage and act like the foot is sore, not much fun driving that way but it sure is nice on the pocketbook.