This is my first diesel so not sure if 18.93 miles per gal on first tank of fuel is good. Is this good or just average?

Good question ekrott! I got 19.2 on my first tank. http://www.dieselplace.com/forum/smileys/Big Smile.gif

Have new lb7, 2000 miles. 19 -19.5 combo driveing so far. Very pleased. Just started useing stanadyne, motor sounds a little smoother

Hello Guys,


Are you guys getting 18 and 19 mpg, http://www.dieselplace.com/forum/smileys/Clap.gifcity, highway, or combo driving and by the way, what is stanadyne?http://www.dieselplace.com/forum/smileys/Big%20Smile.gif


Regards,


DoferGoferhttp://www.dieselplace.com/forum/smileys/Cool.gif

I'm driving in towns, county, hills of NW PA no long trip yet but leaving for Florida in 3 weeks.

Mileage will go to s__t as you start adding the goodies.

Mileage will go to s__t as you start adding the goodies.


Ditto. You guys aren't driving nearly as hard as you should be...


When you get sown to about 15 or so, you're starting to have fun! http://www.dieselplace.com/forum/smileys/HiHi.gif


Ty

The benefits to goodies far outweigh the couple miles per gallon that you may lose. :-)

I just got my LLY and I got 18.2 first tank combo driving and then while working "salting Parking lots" I got 14.5 have right at 900 miles now.

LBY with under 2000 miles ranging from 12 towing a 4500lb boat at 70 MPH, to 24 MPG running 65 on the highway flat ground empty in warm weather. First tank was about 18.9 mixed driving. Cold weather sure drops the mileage.

24 mph highway ????? 18-19 average during the winter?? You guys better start shaping up and get the pedal to the metal. I'm getting around 14 mpg right now city and 18 highway. Where are the summer numbers ( 17/21) ??? You guys are making me want to go out and buy a LLY..

Are you guys checking it by hand or are you going by the dash meter? I drive 17 miles to and from work each day. 1 mile of it's city streets the rest is freeway. First tank on a LLY and it's 15.9 done by hand and 18.3 by the dash meter!

24 mph highway ????? 18-19 average during the winter?? You guys better start shaping up and get the pedal to the metal. I'm getting around 14 mpg right now city and 18 highway. Where are the summer numbers ( 17/21) ??? You guys are making me want to go out and buy a LLY..


Mine's an LBY not an LLY, and the 24 MPG highway was in the Dallas area, winter here isn't like winter every where! Think it was in the low 70's when I got that mileage, don't think the local pumps have winter fuel in them, and yes, it was off the DIC. Guess I better do some calculating to see how accurate it is. I've definitely been babying it though, sure it will drop when I start running it harder. I am surprised how low the towing fuel economy is though, hope that picks up as it breaks in. Edited by: srode

Wow, these mileages sure are better than what I am getting. My LLY averages 14.0, mixed driving. I have been keeping it under 55 and I am on my second tank of fuel. Winter blend. I have bigger tires and torsion bars are cranked up one inch. I hope the mileage improves. Maybe after 500 miles or so, it starts to get better.

<TABLE id=HB_Mail_Container height="100%" cellSpacing=0 cellPadding=0 width="100%" border=0 UNABLE="on">
<T>
<TR height="100%" UNABLE="on" width="100%">
<TD id=HB_Focus_Element vAlign=top width="100%" background="" height=250 UNABLE="off">These numbers are bewildering to me. I live in Southern California, so it does not get too cold over here. The best mileage I have gotten is 17.5, and I that was keeping the speed around 75 on a long trip (no load). I drive about 13 miles one way to work everyday, 12 of those miles are on the freeway and I average about 16.8 between fillups according to the DIC.</TD></TR>
<TR UNABLE="on" hb_tag="1">
<TD style="FONT-SIZE: 1pt" height=1 UNABLE="on">
<DIV id=hotbar_promo></DIV></TD></TR></T></TABLE>

The mileage I posted earlier (19.2 mpg) was a combination of city (25%) and highway (75%) at about 70 mph.

One note for you guys wondering what the heck is going on with my numbers. First, I picked up a little with the Edge program, no doubt about that, 1-2 mpg. Second, that 17 mpg is combination of 80% around town and the rest highway. I figure high 15's or low 16's on strictly around town Rt.1 type driving, not real city, we're talking Maine here. My fuel economy before the Edge and before breakin was less spectacular. I had a loaner gas 6.0 before my truck came in, it got around 10 mpg combo, so I guess we can't complain. By the way, I use the throttle......

Keep in mind that the Juice will skew the fuel economy recorded on the DIC. Mine was within .1 accuracy before I put the juice on. It has been off by as much as 3 mpg when calculated by hand. Mine read 23.5 on one leg of our trip to Vegas in Dec, but only calculated out to be just over 20 mpg. Still great mileage though...


Bob

Hey all


I'm getting 18-19 MPG according to the DIC. Frankly I don't see how you guys can "independently" calculate your mileage unless you've got an external odometer. I'd guess that the DIC calculates mileage based upon the on-board odometer vs. fuel tank capacity. Then again, it may be more "advanced" (read: WRONG) than that.

I'm averaging 15.4 MPG combined, haven't reset it since I got the truck, and last week driving to Tunica I averaged 16.6 in the business section of the meters, plus I get a hell of alot better fuel mileage when I don't use cruise control, is this true with anybody else??

Mine's an LBY not an LLY,





Hmm...


When did GM start building an LBY?......http://www.dieselplace.com/forum/smileys/Ermm.gif


Or did you mean an LB7?..........http://www.dieselplace.com/forum/smileys/Confused.gif


Just curious.


My new LLY/A Dooley got 15.2 first tank, figured by hand. Haven't looked at what the DIC says. It's a bunch better than the old gasser even if it doesn't go up from there, which it should as it loosens up.Edited by: Zeeb

i just dont think you guys are calculating rt......how many miles are you getting per tank?.....my display says i am getting 16 on a good day but real numbers say 14.2.....

Done by hand and these numbers repeat themselves. If you get too good fuel ecomony and you didn't put enough fuel in your tank on that one fill up you'll know it when you do your next fill and calculation because it will look like your mileage has gone to hell. I would stand behind 15 city and 20 highway without exaggeration during the warm months. I think I've lost 2-3 mpg with winter fuel and me leaving the truck running all the time. I also have 20,000 miles on the truck and it has improved a lot since around 10,000.

I'm averaging 19mpg in the cold weather on winter fuel, mix of town and highway driving, as long as i keep my foot out of it (for the most part). It's not as strong of a winter blend here as it may be in some places, I was told it's good for ~14 degree temps.


(I'm measuring using US gallons not bigger imperial gallons)

22K miles on my 03, DMax LB7, Alli, CC. All stock except for 265/75 BFG's and a K&amp;N drop in filter. I have tracked every tank since day one using Excel and my calculations include a correction for the larger than stock tires. 16.1 MPG overall. Best of 19.5 on a long trip running 70-80. Worst of 11MPG towing my 6000lb camper or 4000lb snowmobile trailer at 65-70. My commute is 50/50 city/hwy and I typically get 16.5. I don't baby it and usually drive 10 over the limit.


I was hoping for 20MPG hwy but we'll see about that after a mufflerectomy and a chip upgrade. I know I could get better MPG at 65 but in Michigan the only place we run 65 is on backroads, at 80 on the expressway, you're just keeping up with the flow of traffic.


I have used standayne, and have also tried FPPF Total Power and a cetane booster, but no combination of additives or "preimum diesel" has seemed to have much of an effect on my mileage.


Still...versus my old 5.7 gasser at 13MPG overall.....no complaints!


Fred G

My LLY only has 600 + miles and I'm only getting a little over 12MPG http://www.dieselplace.com/forum/smileys/Cry.gif (all city)!!...Hope it gets better........Triffid

I haven't dumped my log book into an excel sheet but my tanks have averaged about 13mpg low -16mpg high. Stock except the 285's. I don't baby it and run 78mph on the highway which last weekend up and back from Tucson to Phx was 14.5MPG. About 30 miles spent in town. I'm still waiting for better MPG not sure I'll ever get it with the 285's. I got 4k+ miles on the truck.





cmc

People keep in mind the peak mileage is made when driving at Peak torque RPM. So if you go over peak torque Mileage will suffer. Im sure most of you know what that rpm is. I don't but i think its around 1600 rpm. So if you are driving 70 mph I know your mileage will suffer. what we need is a 3.42 or 3.23 gear ratio to make great mileage or drive 55. Just like sammy hagar has said " I Cant Drive 55" I have seen from 14 to 23 mpg out of my truck and it all had to do with the speed i was driving. In fact my worst came on a 750 mile trip from Dwight to Indiana. I got 14.2, But I went 80 to 90 most of the way. My best is just driving back and forth to work where I have some 55 mph speed limits. its 40 miles each way. 18-22 mpg. I also have put on the 265 tires and recaibrated my tire size with the hyper tech programmer.

what is LLY and LBY???

how many miles per tank

Mine's an LBY not an LLY,





Hmm...


When did GM start building an LBY?......http://www.dieselplace.com/forum/smileys/Ermm.gif


Or did you mean an LB7?..........http://www.dieselplace.com/forum/smileys/Confused.gif


Just curious.


My new LLY/A Dooley got 15.2 first tank, figured by hand. Haven't looked at what the DIC says. It's a bunch better than the old gasser even if it doesn't go up from there, which it should as it loosens up.





You got me, it's an LB7, must have been snoozing at the key board while typing.

I haven't dumped my log book into an excel sheet but my tanks have averaged about 13mpg low -16mpg high. Stock except the 285's. I don't baby it and run 78mph on the highway which last weekend up and back from Tucson to Phx was 14.5MPG. About 30 miles spent in town. I'm still waiting for better MPG not sure I'll ever get it with the 285's. I got 4k+ miles on the truck.





cmc





Are you adjusting for the different tire size?

Best so far 420 from a tank. (26 gal.)

I just tried this morning. After reseting the mpg on the computer I was able to get 20.8 on a long 40 mile stretch. That was at 60 mph with three of us in the crew cab and going real easy on the pedal.


I usually get mid 17's with highway driving though at about 70 mph.

My milage on the last 5 tanks is around 16.5 mpg in town driving to work (48 miles 1 way up I35W thru Ft Worth) avg speed is around 50 mph.

If I drive in town (stop & go thru lights) it is around 15.2
On my last 4 road trips from Ft Worth to way south of San Antonio (about 600 miles 1 way running 75 - 85 mph) I get anywhere from 17.8 to 18.8 mpg. I just have not been able to keep it below 70 mph to see what the really good milage would be.
My wife did get 19.4 on 1 tank that she drove at 65 mph when the truck had less than 10k miles on it.

Truck has a Quad 110, straight pipe, amsoil air filter, stock tires, Nicktane & 22K miles. Overall avge going to work is around 16.5 & overall hwy milage is around 18.1 BTW I really do have a pretty heavy foot. Like the old song said . . . . I can't drive 55! http://www.dieselplace.com/forum/smileys/Big Smile.gif

Pretty happy so far!

A few things need to be cleared up here... those of you posting your MPG's from what the DIC says MAY BE WRONG! I just did an 800 mile roundtrip from Mpls to Chicago and did the calcs myself.


According to my GPS the ODOMETER is correct... so I can take the miles and devide by the gallons I fill in the tank and that's the manual calculation. The DIC in my truck said I used 19.8 gallons on one fill, and I was only able to get 18.8 gallons in there with the filler neck overflowing. I did this 3 times and all 3 times the DIC said I used more fuel than I really did. This also means that the MPG reading I got from the "personal trip" or "business trip" or the instant MPG readings is WRONG.


Everyone's truck will vary as the one I had before I traded this one was right on, but this one is off.


EXAMPLE - I drove 310 miles on 18.8 ACTUAL gallons of fuel which equals 16.5 MPG, but the DIC said I used 19.8 gallons and got 15.6 MPG.


With that said, my MPG on the ALL FREEWAY driving was 15-16MPG on the winter blend fuel driving to Chicago, and 16-17MPG driving back to MPLS on pure #2 fuel... I was going about 75 MPH all the way. If I drove much faster than 75 the MPG's started dropping pretty quick, and driving slower I got better MPG's... so if I were driving 55 I would be in the 21-22 MPG range.


All things considered getting 16-17MPG running 75mph is pretty good for the size/weight of the vehicle. I only wish I could run 85mph and still get that MPG, but that's life.


Anyhow with all that said I will be getting my NEW truck with the LLY next month! The TPW is Feb 23rd, and I'm really excited about that... http://www.dieselplace.com/forum/smileys/Big Smile.gif

BTW, as new guy said, the DIC will give out incorrect info, esp in my case with the Quad tuner . (I only wish I could get 26 - 28 mpg on level ground at 72 mph!)

All of my milage numbers are hand calc'ed (miles -vs- gal of fuel).

I dont trust them damn computers. Im sopeaking from experience as I worked with computers for 41 years.


I once got 2 more miles per gal on my Grand Cherokee pulling a Coleman trailer than I do not pulling it you figure.

Do you notice that you get better fuel mileage at 75MPH than 65MPH?

Rick&amp;Danni:


Yeah, when I switch 'er into Georgia Overdrive.

is the turbo noise louder with the LLY turbo?

I just finished my second tank of fuel in my new DMAX. All my figures are from the DIC. I also don't think the dealer filled it all the way up the first tankful. (by the way how big is the tank in a Ex cab S/B ?) First tank 14.9 MPG.. Second tank 16.6 MPG. On the personal DIC readout 18.9 MPG. I am confusedhttp://www.dieselplace.com/forum/smileys/Ermm.gif. Each time I filled it up, it only took 24 gallons. Still its better than my gasser.


As for the turbo noise, its real quiethttp://www.dieselplace.com/forum/smileys/Big Smile.gif


Tim

Does anyone know how the DIC calculates the gallons used? Is it a flow sensor? Calculated by injector "on time? or some other means?

The DIC uses the fuel gauge to make its calculations from. The fuel tank on all shortbed are 26 gal. and all longbeds are 34 gal. . The cab chassic units have an option to have dual tanks. This is the reason for the errors in the DIC as it has to go by fuel level not a true measurement of total fuel used.

ok so it is actually quiet or are you kidding? there arent any around here to test drive that i nkow of. my familys 03 duramax turbo is damn quiet imo.

TCosgrove


You may want to watch your fuel level, it seems if you are putting 24 gallons in you'r almost out of fuel in a 26 gallon tank. Just my .02 Diesel Tech had posted the correct amounts for long bed 34 Gal &amp; short bed 26 Gal in a post above.


Fran

D.T. I don't understand how they could be using the tank level for MPG calculations. I often watch my intsantaneous MPG while driving. Every change in grade or accelerator position affects this reading. There must be something else at work here. Moving my foot even a fraction of an inch doesn't change the tank level a measurable amount but changes my insantaneous readout immensley. It is also my understanding that the trip and other MPG readings are an average of these instantaneous readings.

I have an 03 sbcc4x4.. I check my milage gallons /miles on odometer/tripmeter.. daily to and from work 14.5 hwy 19.5- 21.5, loaded 5er10k FL to MO 11-12.5.. My truck is a LS model and I'm not sure if my truck has a way of calculating MPG through DIC??? If any one could enlighten me how this is done I would appreciate it.. thanks in advance..http://www.dieselplace.com/forum/smileys/Geek.gif

4,000 miles on a '04 LB7 and have yet to get over 14.3mpg.


http://www.dieselplace.com/forum/smileys/Cry.gif

<TABLE id=HB_Mail_Container height="100%" cellSpacing=0 cellPadding=0 width="100%" border=0 UNABLE="on">
<T>
<TR height="100%" width="100%" UNABLE="on">
<TD id=HB_Focus_Element vAlign=top width="100%" background="" height=250 UNABLE="off">


1st 1500 miles I got 18.6 ( city and hwy ). Then it got real cold, now down to 16.5 at 3000 miles. 22- 24 on a 200 mile highway trip ( cruise set at 68 ) LB7 Runnin @ 55-60 I do believe you can get a consistent 24 on highway.


Jeff</TD></TR>
<TR UNABLE="on" hb_tag="1">
<TD style="FONT-SIZE: 1pt" height=1 UNABLE="on">
<DIV id=hotbar_promo></DIV></TD></TR></T></TABLE>

4,000 miles on a '04 LB7 and have yet to get over 14.3mpg.


http://www.dieselplace.com/forum/smileys/Cry.gif





You are in a cold climate (st louis area), and must drive way over 70, or have a heavy foot I think!! I can almost get that towing a 5000 lb boat. Wait till this Summer, you will do better. Edited by: srode

srode....


"Are you adjusting for the different tire size?"


nope... I don't get that technical with my calculations. http://www.dieselplace.com/forum/smileys/Big Smile.gif


cmc

Love my new LLY!


First tank was combined city/highway, mostly 55 MPH for breakin. The DIC said 18.4 and I doubted it but actual milage and gallons computed to 18.4.....LUV it! After first 500 miles I speeded up to 70 MPH highway. Still combined city/highway with a long traffic jam stop and the DIC is saying 17.5 on second tank so far.


3500 Dually, Extended cab in south Texas.

I have a 2001 LB7 I've only had it for about 2 months. I've Religiously kept track of the mileage via an excel Program(and manualy checking for acuracy). I drive about 35 miles a day to and from work (Back country roads, 55mph) and a little around town. On winter blend (thats all I've used so far) I get 15.5 every tank. My Low Fuel Light comes on at about 425 Miles, and a fill up will take about 22-23 gals. Longest trip I've taken on a tank of gas has been 160 miles round trip and miles went up to 16.5 mpg. This is also using Shell DFA(Running a couple tanks right now with out the DFA to see if there is any change). JM2Cents Edited by: Baloo

LB7

Best Ive got was 20.4 at 70mph cruise/freeway.
Worst town with juice and foot to floor 12.7.
Average city before h2 tires 16.7/ fwy 19.5.
Average city with h2's 14/fwy 18.7.

Problemchild -


Is that with the DIC readings or the actual calculated readings?? (and is yours accurate?)


Do you like your H2s? I'm up the the air about what to do with wheels/tires for my new ride...

Newguy

Actual readings at the pump + 13% added to the speedo milage.

You better figure out how to protect the side of the truck from the really bad rock/sand/gravel damage that WILL come from the H2's.

The side of my truck is DESTROYED!

4,000 miles on a '04 LB7 and have yet to get over 14.3mpg.


http://www.dieselplace.com/forum/smileys/Cry.gif





That's because you're treating like the Port and Stbd engines. There is life below 55% http://www.dieselplace.com/forum/smileys/Big Smile.gif


The DMax's wings are just too stubby to get past v1. http://www.dieselplace.com/forum/smileys/Embarrased.gif

Problemchild - thanks for the warning... maybe some BIG ASS mudflaps then... like the ones you see on the huge motorhomes...


I hate rock chips, and I really think the quality of GM paint isn't all that good, especially compared to my VW (it's a diesel too)


Well - that's all folks...

PC!!!!---Ya just gotta update your truck! Rock chips on the side of a truck are a thing of the past. Your chain guns and cannons are also quiet "dated". My ride came with GM's latest equipment. (1) Auto Forcefield--engages automatically to protect the truck from rocks or even depleted uranium rounds (2) Phasers front and back-- these bad boys really lite the world up for furd or durge aliens (3) Photon torpedoes--I cain't leave home without 'em!!! (4) Who the hell needs remote start this day and time?--I leave my MAX in low earth orbit and simply beam up and down as is needed!!!!!---------See ya later. Me and the wife are gonna run over next door for a real MARS bar and a shake!-------------http://www.dieselplace.com/forum/smileys/Cool.gif Phil

Last two tanks I got 21 MPG. This is just short haul local driving here in PA hills.


Looking forward to pulling 5th wheel to FL and see what kind of milage I get.


2004 2500HD LS long box 4x4 LLY.

http://www.dieselplace.com/forum/smileys/Clap.gifHi, I am new to this web site but I have owned a 2002 GM Duramax , Ex Cab with Allison Trans. for 2 Yrs. It is stock &amp; I now have 34000 miles on it . I pull a 30 Ft. Camper that weighs 8000 Lbs. I live in Pa. Near Pittsburgh and have traveled the W.Va. Mountians and the Ohio Flats. I Keep it at 70 to 75 most of the time . I have fun pulling it up the 8% grades at 70 MPH. passing everything in sight ,while my wife screams SLOW DOWN. I have always checked milage the old way , Topping it up to the same spot and using a calculater. It gives me 10MPG in the Mountians and 11 MPG on the flats while towing. I get 18 on the highway at 75 MPH and 17.5 combined town and country. The milage always goes down above 60 MPH . I have come to the conclusion that bucking the wind with a high camper like mine takes as much effort as pulling steep grades. Hence only 11MPG on the flats. All in all I LOVE my Duramax and Allison Trans and will replace it with a new 2004 soon. I vey much enjoy this web site and appreciate the knowlage available from all you Duramaxer's. http://www.dieselplace.com/forum/smileys/Big Smile.gifhttp://www.dieselplace.com/forum/smileys/Clap.gif

6500 miles - winter blend 18.5 on short trips and around town ('bout 15 miles at a time), 20.5 at 70-75 for the 70 mile trip to Reno.


'04 LB7 w/Allison and 4x4


Beats the heck out of my 460 Ford!

Checked accuracy of the DIC fuel econcomy yesterday after running a full tank through it and it was within a half percent of hand calculated on 24 gallons of fuel. Easily within margin of error for filling the tank. I stopped first and last fill up when the handle click off automatically. Will assume the DIC is accurate for now, until I get some larger tires.