Questions...I am a mileage "watcher" and want to get best mileage from my vehicles. From my reading that has steered me to a used LBZ??

However, I would like to also consider the newer LMM.

Question...if mileage is goal...vs specifically more HP/Torque...if you take the steps pf EGR blocker and DPF removal (I think?)...maybe bigger exaust pipes?...does the LMM then equal the mileage of the LBZ????

Seems like it would then be "similar" to LBZ??

Thanks for the input...Minnesota is a non-inspection state. I assume it would not be too hard to get a shop to do the modifications described above?

Other than DPF...are there other "issuses" with the LMM or is it a pretty good set up?

What thinks you??? LMM w/mods OK or still look for LBZ?

Thanks...Tom R

The DPF itself only consumes about 1/3 of a gallon extra every 430 miles or so. That has little effect on true hand calc MPG's. This has been tracked by several on this sight using the Edge Insight monitors to tell when the DPF is cleaning. Simply reset the DIC gallons used at the start of a regen gives accurate figures compared to when she is not cleaning.

The gains in MPG to be made are in tuning - in order to do that the DPF must go...... Of course so goes your warranty and emissions.......

DutchPilot has over 200K on his constantly hauling RV's to Canada. He saw 1.5 MPG increase when the DPF fell off at 70K allowing a tow tune to be installed.

;)

They should get stronger bolts to hold those things on. It's the damnedest thing, mine "fell off" also, along with the cat, (DOC) and muffler.

JT

LMM with mods should get you where the LBZ is. A 2-4 MPG gain with the deletes is very common.

I've owned 2 LB7s a 2002 and a 2004 and my 2008 doesn't come close to what the LB7s were getting with fuel mileage, the mileage is that bad with the LMM. Oh and my DPF fell off too. Granted the LB7s weren't duallys but I don't think that would make that much difference.

I find it funny Duramax-Lmm said it correctly you go to most forums and they will tell you 2-3 miles per gallon gain taking the DPF off. WRONG! I can get 23mpg on a flat flat road and I get from 18-22 on long trips. Those who tell you 2-3 by taking it off is the biggest LIE I have come across on these forums. I see people who have programmers and dpf deletes and honestly they are not getting better mileage than me stock! and that is the truth! I have listened to many LBZ owners who are not getting the mileage I am getting at all. Same motor I have the dpf and different tunning. GM is pressured by the government to get the best out of these they can thier engeneers are not dum I can tell you that. One guy said you only changed the air intake system and got 2 miles to the gallon more another big LIE. That would mean I would get as high as 25 in some perfect conditions I will never get 2 miles to the gallon more changing the air system and doing a dpf delete like Duramax-Lmm said 1/3gallon every 430 miles or so is about right that is some of the best info you will get there. The LBZ getting better mileage than the LMM is another LIE.

every truck is different.......and so many factors but i do know my lbz is better than my lmm and my lbz is turning more rubber.

For what it is worth at stock, I get on average highway, I get 18 to 19, and 20 to 21 going to certain places running usually no faster than 75. Average city is about 15 to 16. I could probably do better, but my foot usually falls asleep on the right pedal, nothing like geting set back in your seat.:D

I agree with others that say you won't see much of a milage increase losing the DPF, but you might see more of a gain if you are doing a lot of short driving when it is trying to do a regen and it never gets to finish.

I average enough in both worlds that I never notice the regen.

my lbz turning stock 245's=15mpg avg. city/highway
my lmm turning stock 265's=16mpg
lmm on flat ground burning a hole tank non stop averages 22mpg/65-75mph.

They all vary a little bit and after the lbz came out the fuel economy went to shit!

I find it funny Duramax-Lmm said it correctly you go to most forums and they will tell you 2-3 miles per gallon gain taking the DPF off. WRONG! I can get 23mpg on a flat flat road and I get from 18-22 on long trips. Those who tell you 2-3 by taking it off is the biggest LIE I have come across on these forums. I see people who have programmers and dpf deletes and honestly they are not getting better mileage than me stock! and that is the truth! I have listened to many LBZ owners who are not getting the mileage I am getting at all. Same motor I have the dpf and different tunning. GM is pressured by the government to get the best out of these they can thier engeneers are not dum I can tell you that. One guy said you only changed the air intake system and got 2 miles to the gallon more another big LIE. That would mean I would get as high as 25 in some perfect conditions I will never get 2 miles to the gallon more changing the air system and doing a dpf delete like Duramax-Lmm said 1/3gallon every 430 miles or so is about right that is some of the best info you will get there. The LBZ getting better mileage than the LMM is another LIE.

Lot of bold statements from someone on their 3rd post. I get 14.5 with a mixed 50/50 city highway. I also had the others in my sig which would get 17 city 21 hwy all day long.

Lot of bold statements from someone on their 3rd post. I get 14.5 with a mixed 50/50 city highway. I also had the others in my sig which would get 17 city 21 hwy all day long.

While it is a bold statement I will have to agree. The 2-3 MPG gains for nothing more than a DPF delete are hype. I made the chalenge on another site for someone to take a 400 mile trip (200 miles out and 200 miles back) with cruise control as much as possible WITH a DPF and then do the delete with STOCK tune and make the same trip and post there results. So far all I have gotten for the suggestion is flamed:eek:

I'm curious what kind of mileage people expect from an LBZ. In my bone stock LMM (well PCV reroute) I got 19+ out of the last 3 tanks (hand calc). That was some highway (65-75) but mostly 2 lane country roads. All highway I suspect I could get somewhere in the 20-22 range. Frankly, for a vehicle of this weight, I'm impressed. Did the LBZ really do that much better?

Yes, I do drive for mileage, but don't have a problem letting the turbo spin-up when needed, pulling onto the highway for example.

Lot of bold statements from someone on their 3rd post. I get 14.5 with a mixed 50/50 city highway. I also had the others in my sig which would get 17 city 21 hwy all day long.
Did not know one became bolder after more than 3 posts ok if you say so.

While it is a bold statement I will have to agree. The 2-3 MPG gains for nothing more than a DPF delete are hype. I made the chalenge on another site for someone to take a 400 mile trip (200 miles out and 200 miles back) with cruise control as much as possible WITH a DPF and then do the delete with STOCK tune and make the same trip and post there results. So far all I have gotten for the suggestion is flamed:eek:
Reason my statement is so bold is I talk on another forum and all I hear is all the gains they are getting with the dpf delete 2-3 mpg IT IS BULL!!!!!!!!!!!!! and a LIE!!!!!!!!!!!!!!!!!!! You can see them 4, 5, 6 months later posting things like I which I had better mileage I only get 14-16 etc. etc. etc. I have yet to see one get better than mine stock unless it is another stock Lmm..... If you think your one spare yourself the embarrasement it a lie and they get old. Nothing and I mean nothing not even the LBZ is getting better mileage than what all these folks are getting with their Lmm's. The statements they are making about the stock fuel mileage are true and correct. Sure you can ROMP on them up and down the freeway and around every corner and only hit 15mpg but that is not what they are doing.

While it is a bold statement I will have to agree. The 2-3 MPG gains for nothing more than a DPF delete are hype. I made the chalenge on another site for someone to take a 400 mile trip (200 miles out and 200 miles back) with cruise control as much as possible WITH a DPF and then do the delete with STOCK tune and make the same trip and post there results. So far all I have gotten for the suggestion is flamed:eek: I could only amagine the flaming you got over that one...... That is because they are trying very hard to believe the lies around the hype and to make it true when it cannot.

The big dif is LBZ's are all broken in - and you can tune a non-DPF truck more easily for better MPG.

Don't know if the "clean-tunes" like Banks has are worth looking at to keep the DPF.

I do know I have seen a 2 MPG increase from new compared to now at 30K on her. (Typical empty freeway trip new was 17MPG - Now it's 19MPG nearly every trip). Maybe more miles will provide more break-in gains, I don't know.

Only real way to increase mileage besides break-in on an LMM is give it a good tow tunes when the DPF falls off.

However - My stock OEM tune and DPF are there to stay.

;)

You also have to consider the trucks that the DPF fell off of, dragged the DOC right along with it. If you do a cat back DPF delete i dont suppose there would be a significant change in fuel milage. With a free flowing exhaust, Turbo-Back, there is a mpg gain regardless of tune used. I personally averaged 17.5 with my DOC/DPF attached while running stock 245 tires. Now i am turbo-back with 285's and average 18.7, running stock tuning. I dont like the way my truck shifts with extra power.

You also have to consider the trucks that the DPF fell off of, dragged the DOC right along with it. If you do a cat back DPF delete i dont suppose there would be a significant change in fuel milage. With a free flowing exhaust, Turbo-Back, there is a mpg gain regardless of tune used. I personally averaged 17.5 with my DOC/DPF attached while running stock 245 tires. Now i am turbo-back with 285's and average 18.7, running stock tuning. I dont like the way my truck shifts with extra power.


I imagine the DOC always would go by-by with the DPF for most.

Your current MPG is the same MPG I am getting stone stock running bigger tires too.....

;)

Lot of bold statements from someone on their 3rd post. I get 14.5 with a mixed 50/50 city highway. I also had the others in my sig which would get 17 city 21 hwy all day long.

At least one more honest person on mileage, Thank You.

Mine 13.5 - 14.5 mixed 50/50 city hiway one time recently I got 15.0:cool:
I celebrated after that, but that was short lived.
Towing my 13,500 5th wheel 8-9 on a good day.

DPF deleted with a stock no dpf tune or a economy no dpf tune, maybe, just maybe .5 mpg increase. For apples to apples compairson.
The real noticable gains are a little cooler egt`s, longer engine oil life,
(just monitor the oil life % before-durning-after a regen you`ll see)
And no more stink in the cab at least from no more regens anyway. :)

To get maybe a 2-4 mpg increase from what people claim you would have to run a much bigger tune to achive that.
Me personally, I would not suggest adding more than 40 hp with a tuner.

But I`m somewhat conservative, besides I would like my diesel to have a much longer life. :D

I could only amagine the flaming you got over that one...... That is because they are trying very hard to believe the lies around the hype and to make it true when it cannot.

couldn't agree more, like I said I made a challenge to prove it and only got flamed for it. IMO if you want to tweak and modify more power too you but don't give them MPG BS as your justification. Hell I did a trip the other day and said what they hey and drove 55 for about 2 hours and average 24 bone stock. Yes that was on the DIC and not hand calculated, which is another bone for me, I have checked my by hand it is is pretty frickin' close when you take into account foaming when filling and all the other varaibles the DIC is problably closer than all these hand calculations.

Apparently the number of posts you have made somehow qualifies you as an expert. (never mind that just got my attention) Fuel mileage has gone down since 2002 because power has gone up, it usually takes more fuel to make mower power, hard to have the best of both worlds.

Add in EGRs and CATs (2003) and DPFs (2007.5) and you loose even more MPGs.

I have 2009 dually and I get about 13 mpg in town and most of the time on the highway I get from 14-15mpg on the highway. I have only once got 16mpg on the highway but I only have 5300 miles on it now. It might get better once it breaks in a little more but I bought a 1 ton not a civic. I love when people say I get 22 mpg cause if they are they are doing that with a 8000lb truck they are doing good. But a lot people always go by the dic for there mileage but if ask them how many miles they get to the tank it nevers adds up to the 22 mpg. But this is my first duramax so I don't know much about them yet so I could be wrong. But I had 6 dodge cummins all the these people say they 20+ mpg with a programmer I thought they also where lairs cause the best ever got of those truck was 18 mpg that was just ever once in while. I must of just had 6 lemon in a row I guess I have bad luck in picking trucks.

My 2500 HD gets the following (all read off of the DIC...I know the numbers aren't super accurate, but they definately will help show trends).

Cruising on the highway at 75 MPH : 17-21 MPG
City driving : 12-15 MPG
Back roads driving: 11 - 14 MPG

Total average per tank when all said and done : 13.5-16 MPG depending on the % of driving type...

I hope to see a little better numbers when the DPF falls off and the truck gets a decent tune in it. For now, I can live with the numbers I am seeing...I sold my TDI Jetta to get a 2500 Duramax...I didn't expect the mileage to come with it...

Who cares? Its a truck. Want great mileage?! Get a Chevrolet Aveo.

"Well..uhh... I like to pull stuff...."

Then find a new hobby.

couldn't agree more, like I said I made a challenge to prove it and only got flamed for it. IMO if you want to tweak and modify more power too you but don't give them MPG BS as your justification. Hell I did a trip the other day and said what they hey and drove 55 for about 2 hours and average 24 bone stock. Yes that was on the DIC and not hand calculated, which is another bone for me, I have checked my by hand it is is pretty frickin' close when you take into account foaming when filling and all the other varaibles the DIC is problably closer than all these hand calculations. I could not agree with you more. I got flamed flamed flamed from guy's when I told them I got 23 on flat flat ground and 21.9 over the sierra's from Reno Nevada to Elk Grove South Sacramento man did I get flamed so bad one guy told me I better go get someone with efi to be able to post things for him. Then he said as for me he don't believe I am coming close to that he said maybe 18 is more like it. Ya right I told him I have nothing to prove to him. It just showed me how they are no where near this amount of fuel mileage that I know I have just like yourself. Honestly I got 1.5 miles to the gallon less almost until I put amsoil in the front transfer case and rear end that is when I seen my large gain I use amsoil in everything. I like moble one and will use it someday maybe but I get amsoil cheaper but pay shipping so it is about the same. I totally believe you because I am there. I do want to put 265's on I think 245's are the stock ones right. Ya I want one size bigger.

Who cares? Its a truck. Want great mileage?! Get a Chevrolet Aveo.

"Well..uhh... I like to pull stuff...."

Then find a new hobby. I hear you onefoxalpha but I think your messing the whole point here everyone cares a bit unless your pretty much rich enough to through money away and I know most people in the USA are not that rich so unless you are you are you like to pay less at the pump also. If we did not like what we have we would not have them that is for sure.

I am getting a 08 tomorrow so i have been reading up on them. My lb7 never got more than 19 and only got about 10 towing. Really makes me wish i still had my 91 dodge with the 12valve cummins which got 27mpg towing a 4 horse trailer loaded multiple time from AZ to CA multiple times. But then again it was a Dodge and a 91 so maybe not. lol! That truck had 320,000 miles on it when a friend wrapped it around a telephone pull and was still running strong. so far i have yet to see any of the new gens run like the 12 valve Cummins and probably never will. But you can always dream

I must be the only LMM out there with a 50/50 comb. of city/hwy driving getting 14.5 STOCK. So since STOCK is where you are supposed to get the best gas milage. My truck may or may not be broke in depeding on YOUR opinion (15,000 empty, 15,000 towing 12-13k) and for the record, I drive with a very light foot. I suppose I might be able to get this "20+" empty if I could find a flat road with a nice tailwind, speed up until it shifts to sixth then back down to 50-55. But I'm not sure who drives that when most roads at least in my area are at 65 and if your not doing 62+, your getting passed by big rigs.

Of course, you can also argue that my huge increase in tire size from 265's stock to 295's are taking me down from the 20+ highway that I should be getting down to the 16 highway I actually am. :rolleyes:

It does get old hearing of the people that love to come on and say buy a geo. Love that statement.

Also, for the record, I get 8-9 towing. Its fun filling up every 190-200 miles.

And for those that wonder how much my speedo may be off messing up my DIC readings. Using a GPS, after 100 miles, my odometor 98.5 and my speed is off by approx. 1 MPH at 65.

And yes, I do think its a bold statement to come on to a new site with your second post and call a bunch of people liars.

Flame on gentlemen. Cheers :rolleyes:

Moved to Exhaust and Emissions Upgrades.

Been reading this thread and decided to chime in. I was in the same boat about the dpf. Until one day I took my normal trip to work 32 miles. I have a stop sign at 5 miles, one at 15, 5 more miles a stop light and the last 7 miles are on a highway till i get to my work place. With my truck before deletes (picture in garage) on the stock tune not stock suspension I got 14.5 mpg. The regen would use up almost a 1/4 tank of my hard earned money to go on this trip. So the deleting began. First I took off the DPF. With the quad on stock tune no dpf the milage went up to 16. Plus No REGEN so no wasted fuel (Makes me feel better). Second I took off the DOC. This time I decided to up the tune to 70 HP no dpf, I have been getting 17.5 to 18 mpg. I did try the stock tune without both but got better mileage on the 70hp tune. Third step I have taken the muffler off. I have yet to drive this trip to work to see if it goes up again. The next week or so I will be driving it on this trip. The last long trip I did was on my honeymoon we went to tennessee from Northwest Indiana and I got 20mpg highway with the dpf no programmer. I have not had any highway milage since the deletes but soon I will, so I can get some numbers. So that being said Deleting the dpf and the doc I have seen 3.5 mpg on my normal trip to work like many ppl have stated. I think its pretty good for a lifted truck with 33's. One more thing I used to fill up at around the 350 to 360 miles on the trip. Now I can make it up over 410. I use up almost every gallon in the tank every week. ALL hand calculated for those who don't believe the DIC but in my case the Dic is spot on with my hand calculations. Thank you for reading and I am happy with my results.

I really don't understand the anger in the posts from sticky and others claiming high MPG's. Are they ardent supporters of Al Gore and his "Global Warming"? Did you guys design the DPF system yourselves? It is pretty much common knowledge that more restriction limits power and or takes more fuel to make horsepower, especially with a turbocharged diesel engine.

I have an 08' LMM and if I really work at it I can get 15.5, hand calculated. I've tried on several tanks, never getting over 2000 rpm while accelerating, never driving over 60 mph, not pulling a trailer. I cannot get it to do any better. It has 30K miles on it. Pulling a loaded gooseneck, I get between 6-8 mpg. Granted, a loaded gooseneck that I pull is around 32K GCVW. My last truck was an 03' LB7 and I routinely averaged 18-20 driving normally and 9-11 pulling a loaded trailer. Admittedly, each engine is different, but I just don't understand the argument. Those of us that have low mpg LMMs have no reason whatsoever to exaggerate our misery.

Been reading this thread and decided to chime in. I was in the same boat about the dpf. Until one day I took my normal trip to work 32 miles. I have a stop sign at 5 miles, one at 15, 5 more miles a stop light and the last 7 miles are on a highway till i get to my work place. With my truck before deletes (picture in garage) on the stock tune not stock suspension I got 14.5 mpg.

The regen would use up almost a 1/4 tank of my hard earned money to go on this trip.
BS - A regen has been proven time and time again to use 1/3 of a gallon extra fuel, no real effect in MPG over 400+ miles between regens - Those of us with engine monitors like the Edge Insight know what or rigs are doing from hard numbers.

So the deleting began. First I took off the DPF. With the quad on stock tune no dpf the milage went up to 16. Plus No REGEN so no wasted fuel (Makes me feel better).
Of course, but that's all, no MPG gain from just the DPF falling off. MPG gains are seen in tuning.

Second I took off the DOC. This time I decided to up the tune to 70 HP no dpf, I have been getting 17.5 to 18 mpg. I did try the stock tune without both but got better mileage on the 70hp tune. Third step I have taken the muffler off. I have yet to drive this trip to work to see if it goes up again. The next week or so I will be driving it on this trip.

The last long trip I did was on my honeymoon we went to tennessee from Northwest Indiana and I got 20mpg highway with the dpf no programmer.
Of course - the DPF alone does little to effect MPG.


I have not had any highway milage since the deletes but soon I will, so I can get some numbers. So that being said Deleting the dpf and the doc I have seen 3.5 mpg on my normal trip to work like many ppl have stated. I think its pretty good for a lifted truck with 33's. One more thing I used to fill up at around the 350 to 360 miles on the trip. Now I can make it up over 410.
Of course - tuner results - not DPF delete results.

I use up almost every gallon in the tank every week. ALL hand calculated for those who don't believe the DIC but in my case the Dic is spot on with my hand calculations. Thank you for reading and I am happy with my results.

;)

Maybe "Sticky" is using the imperial gallon to figure his MPG?:p:

I will mention something with regards to the amount of fuel used during regen: When I first picked up the truck it would use a significant amount of fuel and take about 20-30 minutes of hwy driving to complete the regen, It would stink up the Cab and smoke and haze a bit. I took it in to have the downpipe re-aligned and cure the smell in the cab deal. This seemed to cure the smell and the regen time was cut in two as was consumption.

I belive it was mentioned on an other forum (maybe this one too, I haven't been here too long) that if you have an exhaust leak allowing cooler air into the exhaust during regen it will take longer(and use more fuel) to reach the required temps for complete burnoff. Maybe Sticky has one of the rare trucks whose DPF system works properly? I also remember that the regen was stated (by the same GM tech who mentioned the leak thing) to use no more than 3 gallons of fuel.

Anyway the loss of my DPF added an easy 80mi to my highway range unloaded.

Maybe "Sticky" is using the imperial gallon to figure his MPG?:p:

I will mention something with regards to the amount of fuel used during regen: When I first picked up the truck it would use a significant amount of fuel and take about 20-30 minutes of hwy driving to complete the regen, It would stink up the Cab and smoke and haze a bit. I took it in to have the downpipe re-aligned and cure the smell in the cab deal. This seemed to cure the smell and the regen time was cut in two as was consumption.

I belive it was mentioned on an other forum (maybe this one too, I haven't been here too long) that if you have an exhaust leak allowing cooler air into the exhaust during regen it will take longer(and use more fuel) to reach the required temps for complete burnoff. Maybe Sticky has one of the rare trucks whose DPF system works properly? I also remember that the regen was stated (by the same GM tech who mentioned the leak thing) to use no more than 3 gallons of fuel.

Anyway the loss of my DPF added an easy 80mi to my highway range unloaded.


No the TUNE added to your MPG. The DPF just got lost in the process... :)

No the TUNE added to your MPG. The DPF just got lost in the process... :)

I humbly disagree:o:. I ran the Evo R with the DPF on Level 1 (+40hp-ish) for a month and had no difference in gas mileage.

If anything I've found the Evo tunes make my mileage marginally worse.

First off Duramax-LMM you need to read my first post again. Where I said I took the dpf off and had the programmer on the stock tune. Let me Bold that so you will see it. I used the STOCK TUNE no DPF. Meaning the same tune from factory gained 2 mpgs. Then I changed the tune. So your telling me that if I were to take the same trip again on The Stock Tune that my milage is not going to be better than 20 mpgs. I call that BS. But thats why this is a free country you can say and think what you want. O and I have witnesses that my truck used a 1/4 tank on the regens. Maybe you got a special truck i don't know, I am telling you what my truck did not what all the LMM's are doing. So don't tell me the mileage didn't go up after doing the deletes I have seen it with my own 2 eyes on my truck.

I don't own an LMM but i find it very difficult to believe that you don't gain anything when removing a DPF. DPF's are a filter, thus exhaust gasses have to be forced threw whatever they are made of. That is a restriction, and anytime you remove a restriction from an engine you will have better performance. Like cats on any engine. Those are actually a stright threw design and when removing them you get better mileage and power. This has been show time and time again.

You might be right that they don't gain you 2-3mpg, but they have to gain you something.

........ this is a free country you can say and think what you want........

True dat.

U can think U burned 1/4 tank in 32 miles all day long. 32/6.5 = 4.9 MPG. Not bloody likely in a stock truck. Gee maybe it was the lift, the wheels, and the tuner on "stock tune" that caused lower MPG's then...... Ya thunk!?

:D

I think U won't get far down the road with no DPF and the OEM tune. A "stock tune" from a programmer is NOT the same dude.

:rolleyes:

True dat.

o well, your right I am wrong, I done playin the game your smarter then me, I was just giving tom my results. Peace out.


P.S. no tuner was installed at the time i had the dpf. I bought the truck with everything you see on it and the speedo was correct. Yes I had GM check it out for me they told me no tuner was installed at that time. So do i believe the wheels and lift had an affect of course I did. Was there a problem with my dpf system? possibility, but I don't have to worry about it now. This is my last post on this subject.

Roar!