2001-early 2004 LB7 Duramax Fuel Economy Poll

[colt49]

1. MPG
   Mileage is constantly 22 or 23 on highway In town is20 or 21 4K miles #2 fuel Flying J Cheyene Wy.06 LBZ 4x4 Allison Reg. Cab

Flow Pro Exhaust 4.5" Stainless EDM Fits

[DmaxMaverick]

1. MPG
   Mileage is constantly 22 or 23 on highway In town is20 or 21 4K miles #2 fuel Flying J Cheyene Wy.06 LBZ 4x4 Allison Reg. Cab

Flow Pro Exhaust 4.5" Stainless EDM Fits

Those numbers are pretty impressive. Are you using any type of electronic power enhancer? Larger than OEM tires? How are you calculating your mileage? Pencil/calculator, or DIC?

[colt49]

This truck is mostly stock exhaust is customed synthetic fluids except motor still breakin cycle on it. Very steady driving cruise control user and slow down and vary speed for break in. Will not install any turners or air intakes, stock is totally fine. This truck will be a good one it's just something you know when you start breaking it in and the power and strength it has. This is the smoothest tranny in the world to me. It downshifts at stops and you save brake use by tons. GM makes my truck and I'm glad I bought this one. The others are nice too buy this one is my vote. Price was real nice compared to the other guys by thousands and no intrest loan was even better. I've owned the other diesels since 93 Dodge Cummins, 96 Powerstroke, and now this one. The others sold for prime bucks because of diesel and they were ok to own but nobody on this planet has this GM setup. My right foot can take this thing to 100 mph fast it's nice to have.

[jay menna]

i recently switched to 285/75/16 and my mileage droped almost 2mpg. is that normal. also with 285's how off is the odometer. i heard almost 5%?

[SoTxPollock]

JUST COMPLETED THE CALCULATIIONS.
100,278 MILES, 5,394.74 Gallons of fuel used, = 18.588 MPG average for the first 100.

I knew that Edge was going to make it drop off!!
Long live LB7's.

[ickyray]

The poll can be misleading, there are different axle ratios which will affect the mileage noted. I just pulled a 24 foot TT through the Rockies for 1400 miles and average 15mpg imperial. Kept to highway speeds plus 10 over, nobody was waiting for me! Truck has 3.73's and 4X4.

[DmaxMaverick]

The poll can be misleading, there are different axle ratios which will affect the mileage noted. I just pulled a 24 foot TT through the Rockies for 1400 miles and average 15mpg imperial. Kept to highway speeds plus 10 over, nobody was waiting for me! Truck has 3.73's and 4X4.

All Duramax equipped light trucks are available with only the 3.73. Any other ratio would have to be owner installed. The 8.1L and 6.0L gassers have the option of 3.73 or 4.10. Tire size changes will effect mileage, though. 10 over with trailer in tow, and no paper trail??

[SoTxPollock]

Yesterday at the station I was adding my fuel supplement and started to pump diesel and two guys walking to their truck made a comment. That won't help it will still only get 13mpg. I glanced at his truck it was a chevy gasser.
I told him I have an average of 18.58 for a 100, 000 miles now and not all of that is easy driving. I've towed some pretty heavy loads. He said oh, you got the Duramax, took a big gulp of his Coors Light and said come on Joe lets go.Got in his truck and drove off. I don't think he believed me, or else he was kicking himself for not driving a diesel.

[Texas Hunter]

2001 4x4 HD ext cab. 275 tires got 19 to 21 mpg. 200100 miles. Injector pump @ 25000m, water pump at 100,000m. just traded 3 weeks for a NBS GMC 6.0 gas 6-speed and traded yesterday for NBS DURAMAX.....Should have known better........but I'm old and allowed to make misteakes....

[Ryan03]

03 d/a 2500 reg cab , 4x4, 3.73s, 265s, 18 city stock, 23 highway stock, 16 city juiced level 2, 21-22 juiced highway level 2. Hand calculated. 70 to 75mph highway, mostly flat with some long grades here and there. Seems to get better highway mileage on the button rather than the pedal.

[oneton]

Long time since I last posted but after reading this thread again I had to post my recent milage record. Had to make a mad dash to WV (from FL) for the passing of my Father-in-Law just about a month ago. On the way up I didn't even bother. It was just one speed(as fast as I could get away with). But on the way back things were a little more relaxed I got 21 mpg in my 02 4x4 CrewCab dually that just turned over 160,000 miles (original injectors and bone stock). Now mind you I had nothing but the four of us and the luggage in the truck but it's wasn't too shabby for a 7000# tank. LOL







David
__________________

[Philsauto]

I added a Bully Dog downloader and set it on the 1 power level on the way to Phoenix from my home in Hemet. I ran 70-75 mph and got 18.5mpg. On the return trip, I changed the power level to 2. I got 21 mpg on that trip and 22 mpg on a subsequent trip, though I ran that one at around 65 mph. I was pleasantly surprised by this.

[pimajim]

With 100K on my 2001 Duramax I have averaged 20mpg
with no load, 15MPG with a 3000 lb truck camper, 10MPg with
a 33 FT 5th wheel trailer. Interesting, recently I got new Cooper Tires, replaced my old Michelin's, Coopers lowered my mileage to 19???
This is a stock truck except for the L&N air filter. Most of our driving is rural mountain areas.

[2500HDTalley]

I was getting 13 average. Did some research as I had a problem the dealer mech's couldn't find. Lead them to the fuel injector area and they found my injector pump had gone bad. Once this was fixed I got 18 average. Dropped from 15w-40 synthetic to 5w-30 synthetic for the winter and am now getting 19.5 average.

[Idahobidcaller]

I have been getting 16-18 around town and 20 highway on my '01.

[reparkerjr]

Mileage is greatly affected by driving conditions. I get 16-18 mpg driving in town stop and go. On the highway I get 20-23 mpg depending on speed. My best was towing a 6 ft utility trailer at ~ 50-55 mph descending from 8000 to 6000 feet in 200 miles; I got 23.2 mpg. Typical is 21-22 mpg at 60 mph decreasing to 19+ mpg at 70 mph.

reparkerjr

[npauli]

I just bought my first diesel (see sig). The first full tank I ran was maybe 1/3 on the highway at 60, 1/3 in town, and 1/3 interstate at 70. I got 20.5 mpg!!!

I'm thrilled with my LB7, especially since the miles/dollar work out to be only about 10% worse than my gas truck, despite being 3' longer, a bit taller, 4wd, and a good ton heavier.

[Fightfan]

I've owned a few trucks for my remodeling company. I had a 97 GMC 1500 Z71, an 88 chevy 1500 extended cab LB, a 92 GMC 3500 Vandura with 6.2L N/A, and my 01 Silverado. Hands down the two diesels were much better all the way around. I could easily get 450+ miles out of my van on the highway. I've just done the upgrades to my Silverado, so I don't know what the mileage is yet after the fact. Bottom line: WOOOHOOO for Clackers!

[JDiesel03]

My 2003 LB7 (3500 4x4 dually)with breathing enhancements(ram air and 4in exhaust) just did 2500 mile mostly freeway trip largely on cruise at 75mph for overall round trip average of 19.6mpg. Lightly loaded with about 1500# of gear in the bed. My mileage starts dropping rapidly at over 65mph....trips holding to 65mph have netted me typically about 24mpg. Love it!

[NeilLB7]

On a totally stock 2002 HD2500 Allison Ext Cab 4x4, all hand calculations, purchasing from the same station and pump, filling from 1/4 tank each time, using Stanadyne PF each fill up...I've come up with the following over the last 11 months.

Highest 18.85 MPG.
Lowest 16.90 MPG (I did alot of city driving this go-round and was a little heavy on the pedal at times)
Furthest Distance from 4/4 to 1/4 tank (fill up point) = 392 miles (I do not go below 1/4 tank as a personal preference)
19.878 gallons average purchased at fill up.
Total overall average MPG = 18.01
Average price per gallon = $2.629/gallon
Total miles represented to produce this data in 11 months = 13,233 MI

The truck has 142,000 miles on odometer, no modifications at all, original injectors, Mobil Delvac 1300, Mobil Syn gear lubes, Valvoline Dexron III ATF, Mobil1 5W-30 transfer case lube, OEM Bridgestone tires etc etc. About a 60/40 ratio of hwy vs. city driving. All empty miles, no towing. 65 MPH highway shows about 18-1900 RPM.

So...unless new injectors and such would really improve MPG's...I don't see how people get anything significant over 20 MPG Avg. My friends claim to...but they have zero data to support the claims.

Now keep in mind this is all average MPG's for me. Which is all I pay attention to. Because I'm buying diesel when my average driving empties the tank.