Im super pissed - hand calculated mpg on first tank in the 05 Xcab LB and got 13.3 Man After thinking about it this sucks! My 6.0 gasser got 11's in the summer, and 10.4 or so in winter. I wonder if I made the wrong chioce swithing to diesel......:(

Just take it easy, you will love it.
DAN

You will have to give it some time - these diesels take time to break in etc. I am now just over 5k and I'm getting 17.4 'hand calc'd' on the highway. You'll find from most on here the LLY is not geting the same as the LB7. It's a bummer, but it is way better than my 6.0 was. Especially this summer when I start pulling the trailer and regular gas is consistently at 2.30!

What is there to be upset about? By your calculations, your getting 20% better fuel economy already. The Duramax is a much more powerful and capable truck. Yes, the price of diesel is crappy but it will come down. Just give your truck a chance to prove itself. You will love it!!!!!!!!

As you can see below we have the same truck except mine is an '03, LB7. I've got 265 tires and use an additive and I'm getting 14-15mpg on winter bled. Before I started using additive, Stanadyne Performance Formula, on winter bled I was getting 13mpg with 245 tires. I don't see any raise in fuel economy on summer fuel using the additive. I get around 17.5-18.5mpg, best ever on the highway was 19.66mpg on summer fuel.

So unless you're in a warm part of the country where you're getting 13.3mpg on summer fuel, you look like you're in the ball park.

See you are a new member. Ah I remember it like it was yesterday! :rolleyes: You might as well get yourself a cold 6 pack, sit down at the computer and do a search on the following: MPG's; exhaust; programmers; towing; oil/filter; air/filter. You will gain valuable intel on your truck and avoid a lot of frustration.;)

In time you will really like this truck. Welcome to the DP and enjoy your truck! JJ :)

Hi,

Not attacking anyone here.......... Just sharing my opinion. You will never find a diesel that will give you top milage out of the box. You have to break them in, put some miles on them, like in the thousands of mile range. Sit back, and enjoy the ride.

Take care

Will

thanks everyone....i think im goin to cry (sniff sniff!!)) just kidding

i hear what you all are saying..... and I understand its not the LB7. Dont get me wrong I love the truck, jsut hoped for better mpg. Also would prefer to not get beaten by the Cummins folk. I hate cummins folk. :cool:

Im going to put on the hard cover, hopefully that'll add a mile or so. maybe not.

i have been thinking about putting the tailgate in the shed for a while to see if that affects the mileage.

ok, here are a few questions:

what size tires do you have on your truck?
how fast do you drive it?
how heavy do you hit the gas pedal?
where do you buy your fuel?
where do you live?
are you uising any additives?

The answers to these questions may help in answerring your fuel question.

just give it time..I also had a 6.0 HD previously..got no better than 10mpg city AND highway... my Duramax got 14 the first tank just in the city. highway got at least 18...thats almost twice as better mileage.

I know diesel is expensive right now, but I am stoked I get this good of mileage with this heavy ass truck!! I fill up at most 3 times a month as before I was filling up every 3 days.

relax..give it time.

My first tank was 11......it's on it's 5th now and has climbed up to as high as 17 and 12ish towing.....hand calc'd.....like the guys said....relax, it'l come 'round.



.

dentman4054,

I took delevery of my LLY on Dec. 13, 2004. The truck had only 10mi. on it.(Braking it in during the winter kinda sucked)

The 1st 818mi. I only got 10.2mpg.
The next 1654mi. I was getting 21.0mpg.
Then the next 2753mi. I'm getting 21.1mpg.(playing with it more and still getting over 20mpg, not bad for a 400ci 300hp 4x4):h . The 6spd may be helping?:confuzeld. Haven't done any towing yet.)
The highest mpg on one tank was 21.8mpg., the lowest was 19.6mpg.
As you can see in my signature I have a Work Truck and they do not cone with one of those fancy DIC's. I have to do the calculations by hand.

Just give it time, it will get better.

My last truck was a 98 Chevy 3500 SWR w/350ci-5spd manual, averaged 11.0mpg empty. I'm so glad I got the DMAX. POWER+MPG=:D
I'm planing to keep this truck at the very least 15yrs or more, and SLOWLY up-grading it, but be careful, these guys will give you the itch a lot sooner than you would expect.):h

I've heard it said that after you've broken in your truck that you need to latch on to something real heavy and give it a pull. Only then will you realize your best economy, FWIW.

T_REX _ interesting theory... i had a similiar experience with my 6.0 gasser. After a heavy tow to atlanta and back it performed alot better. Before would not lay tire, now lays tire at will!


NCMIC here are the answers

what size tires do you have on your truck?
stock which is 245 16 's I believe
how fast do you drive it?
easy in town speeds, not aggressive on first tank
how heavy do you hit the gas pedal?
never hit it from a stand still a dozen or so aggressive hits at speed though
where do you buy your fuel?
only one puchase so far.... BP off Interstate 79 (PA)
where do you live?
Pittsburgh, PA
are you uising any additives?
Have Amsoil Cetane booster have not tried it yet.

ok, you can try the cetane boost as it may help. Your area is, more than likely, on winter fuel mix, which will lower yoiur mileage. I would say, once you are on summer blend, you'll see the increase.

Myself, I have seen a drop in mileage with BP fuels, in my LLY. I lose about 2mpg with BP. I try to find chevron or shell premium and have seen up to 18 hwy and 16 city, with 2500 lbs of materials in the bed of my truck. I normally drive 80-90 hwy and just 5 over in the city. I do flog it at take off and play with the throttle on the highways. I have almost 74k miles on my truck now.

I can say, be patient and maybe try another fuel station. Also, add in some cetane boost, it will help in start up and i think better burn. try to add an additive, without alcohol in it, with lubricity. Stanadyne, FPPF, Primrose are good ones. some are using the Power Service stuff as well.

Good luck and I hope this helps.

[QUOTE=NCMIC] try to add an additive, with alcohol in it, with lubricity. Stanadyne, FPPF, Primrose are good ones. some are using the Power Service stuff as well.


Whoa! I think you mean and additive with NO alcohol in it!?!? The GM TSB specifically states that Racor and Stanadyne are okay because they do not contain alcohol.

sorry, i meant without. my fault for not proof reading.

That's what I figured with the type of additives you were listing. I just wanted to make sure he did not think that he needed the alcohol.

Dentman,

As a fellow (P.D.R.) specialist says to another. Go push some more dents. J/K No insult intended. Don't worry about your truck, the aforementioned replies are all corrrect. You will see adramatic increase in MPG after 10,000 miles. My truck was the same way and I came into this forum with my guns blazing. After a few soothing words from Max Power and the like, I fell asleep at my computer with my thumb in my mouth and never mentioned it again.

I would like to add that I had all my injectors replaced, I did notice about a 3-4 MPG increase. My truck was built 01/20/2004. They have made it a lot tougher to get injectors changed. All techs are required to send a snap shot off there tech II to GM for final approval. If your balance rates are within specs, too bad. Mine were on the cusp. Fortunately I know everyone at the dealership and the service manager approved it, no questions asked. I highly recomend Stanydyn. works great with my truck.

XR

Im super pissed - hand calculated mpg on first tank in the 05 Xcab LB and got 13.3(

Since you mentioned that this was the first fill, I am wondering if you have acurate fill data. Assume the dealer delivered the truck with a "full tank" as shown on the gauge, but did not fill the tank to the top of the fill tube. You then fueled the truck for the first fill to the top of the tube. The actual gallons of fuel shown on the pump would be somewhat higher than the fuel consumed from the delivery mileage. This would result in the calculated mpg being lower than the actual mpg.

Go for a couple of more tanks. Make sure you fill to the same level each time (at the top of th fill tube) and be sure the truck is level each time. Hand caculate everything. The DIC numbers are not aways accurate.

It is a heavy truck and it takes a lot of fuel to get it moving. Fuel mileage will drop like a rock if much of your driving is heavy stop and go. I get around 15 to 17 mpg in moderate city driving with summer fuel, stock tires.

Life is waaaaaaay to short to worry about fuel milage. Now if you wanna cry about somethin, lets all cry about FUEL PRICES. 60 bucks for a fill up yesterday.

Im super pissed - hand calculated mpg on first tank in the 05 Xcab LB and got 13.3 Man After thinking about it this sucks! My 6.0 gasser got 11's in the summer, and 10.4 or so in winter. I wonder if I made the wrong chioce swithing to diesel......:(
Give the friggin truck a few thousand miles...My old LB7 didn't really come to life till after 20K and it was chipped too. My LLY was been sitting at 17mpg since day one I only have 8K on it and I'm waiting till after 20K till I ***** and complain.

Life is waaaaaaay to short to worry about fuel milage. Now if you wanna cry about somethin, lets all cry about FUEL PRICES. 60 bucks for a fill up yesterday.
Damn!!! Im dreading my next fill up, I thought 45 bucks was crazy on my last one!!

My '05 Chev 2500HD crew cab 4X4 Duramax/Allison has about 2K on it and it claims(truck computer) to be getting high 16s and low to mid 17s.

I'm not even going to bother trying to hand calc. MPG until it has at least 5K on it.

you guys are kewl!!! thanks for all the responses F the gas --- Ill buy more!!!

I have about 4300 miles on my ext/4x4 b4 i put the edge/attitude on i was getting about 12-12.5 city.. now with edge on 3 sometimes 4):h and fueling on 5 last 2 tanks have been 13.5-14.0 and im not going to say i baby my truck):h .. so mileage has to be getting better with added mileage...

and how can i complain about mileage and cost of gas.. with my stang with last motor 1 1/2 gallons 1/4 mile at a time costing me 6.80 a gal.:cool:

Dentman/SS,

FWIW I've done the topper/cover/tailgate removal thing in an attempt to increase MPG's with minimal, if any positive results. Turns out there have been numerous studies where the concensus seems to be they have little if any positive affect on MPG's. That being said I do love my Truxedo cover to keep things clean and dry. Later. JJ :)

I have just now hit 14,000 mi. on my LLY.... I am getting a grand old 12 mpg on the Last 2 tanks have been riding on Level 3 - low-boost Fuel on 1......

285 BFG, 4" exhuast and the Edge of coarse!!!!!


Explain this crap.. And yes I thouw the P1093....


Other than that I love my ride..


BIG


BTW: I feel the guys who claim 20 mpg are BS sometimes!!! Becuase I am very maticulas(sp.) on everything and it hasmn't gotten any better...

BW, have you had your truck reflashed? JJ :)

BW - Are you also correcting your mileage due to your 285's? I have to correct mine by 3.9% with 265/75's. It does not make a bunch of difference, but it usually is another 12 -16 miles per tank. If you have 285/75's, you are looking at an additional 7.5 miles per 100.

Not that I'm actually getting 20 - I also am not sure how many LLY's are actually claiming this, but I am skeptical as well. The best I've had was 17.4 (all highway w/o the Juice) with all corrections. I've not had a chance to check it with the Juice since I only had it a week before it had to go back for the update.

BW, have you had your truck reflashed? JJ :)
Got the re-flash, got it done as soon as i heard about it, at like 3,500 miles maybe...

The tires were calibrated to a 32 x 10.50 size, The local gusy aren't up to date on stuff SUpposedly, their wasn't a 285 option on his Tech II he claimed....


Have had these results on mileage since then!!!!

7.5 difference per 100 miles still only gets me at 13 MPG!!!!!

BIG:(

Dang those ever elusive MPG's! :o: BW21, injector balance rates been checked to? The usual tire pressure, air filter, oil/filter stuff been covered to? ;) Really cold weather will kick mpg's in the butt as well. :eek:

I'm kind of a MPG freak in that I check every tankful by hand. I'm running the OEM tires so my odometer should be fairly close. Driving a bubble butt dually and using my DP MPG calculation method I consistently get between 14-15 mpg's around town, then somewhere between 17-19 on the highway if I keep it below 65mph. Not what you want to hear I know but this appears fairly consistent with a lot of LLY owners. Unlike others I started out getting pretty good mileage. :)

Runs great you say. Do you get lots of black smoke when you romp on it? :confused:
You have upgraded the exhaust so that should only improve your MPG's. You might post on the "Ask the Tech's" forum, that 's where the techie types hang. Good luck. JJ :)

If the Edge is in Stock, it bairly smokes at all... I run AMSOIL in everything, change oil at 4,000 regardless of its supposed life and check air-pressures frequently...

I dont throw my MIL, unless the EDGE limps the Ally.

I am literally confused by people claiming 20 mpg!!!!

Other than 12 MPG, truck is EXCELLENT!!!

Weather here in NC is moderate, I hope this gets better from here on out witht he weatehr warmign back into the 80's...

BTW: I run Lucas or Diesel Kleen crap at evetank pretty much....

BIG:(

18.5 is what i get. 20 would be nice.

BW21: If the Edge is in Stock, it bairly smokes at all... :confused:

So if you run the E/J at level 3, low boost at 1 does the truck smoke badly? This may tell us something. JJ :)

I get no more smoke in STOCK than i did when it had NO EDGE or Exhuast!!!

I romped with Juice on Level 3 and Low Fuel Boost on Level 1 today.. I don't really see any smoke really... I am goign to the gym now and will try some more 3/4-throttle stop light pulls and report back...

BIG

BW, slowing narrowing it down, considering 2 possibilities for now: (1) Just how freakin' big is Big Will?):h ; OR (2) Have you changed the fuel filter recently? :confused: I asked previously about injector balance, was this checked? JJ :)

Romped on it on the way to the Gym, Level 3 and Level 1(fuel) basically NO SMOKE..

With Level 3 - and Level 5(fuel) usually a small puff and trail... 5 and 5 of coarse will almost stop traffic..

I changed the Fuel Filter at 7,000 and changed it just 2 weeks ago at 13,800...

I plan to run 2 more tanks staying at Level 3 and Level 1 while staying out of it hard, then I will have a 3-tank comparison, however it will be getting into the 75*+ range around here this week, that may effect ti some...

Will keep informed..

THANKS
WILL


EDIT: Injector Balance hasn't been checked, Local Dealership wants $75 + time to put a Tech II on it... Thats BS... They say they ahve to charge since it isn't throughign codes!!! They are idiots here anyway, so I don't want them workign on my truck, they said that I couldn't even be in the shop while they scan it!! WTF....

BW, if there are any other GM/Chevy dealerships you can go to you might try them. Complain about low idle surge, hesitation, whatever it takes to get it on the Tech II. Still might try posting on the ask the tech's forum to see what they think. Several of them are Master Technicians and give us the benefit of their experience/knowledge for free. Just one more benefit of being a DP member. JJ :)