LBZ Fuel Mileage

[rtigert]

Picked up the truck in Joplin, Missouri 404 mile trip home. Accelerated/decelerated probably 200 times during the trip, never on cruise, continuously loading and coasting the engine. Averaged 72 mph, DIC said 16.1mpg, hand calculated 17.65mpg. I couldn't be happier at this point!

[EdHale]

I picked up my new LBZ on 7-5-06. It is a GMC CC SB and is bone stock including stock tires. Here is my mileage so far. Some of these fillups are towing a 4,500 lb boat and trailer, some with a 900 lb empty boat trailer and some with no trailer. The 19.5 mpg was with no trailer and 75 mph over 250 miles. The rest is a mixture of highway at 75 mph and 2.5 miles a day to work each way (not helping at all).

Total truck miles MPG
244 18.5 no trailer
478 15.0 4,500 boat
806 15.5 4,500 boat
1,185 19.5 no trailer
1,512 17.5 no trailer
1,783 15.6 no trailer 6,500 boat for 10 miles
2,066 17.8 empty boat trailer
2,306 16.8 empty boat trailer

I have to say the 16.8 was partially due to entering the interstate, with the empty trailer, and a "youngster" in a souped up Honda Accord (you know the one with the big oversized muffler that sounds mean!!!!) attempted to pass me while I was still in the acceleration lane. I just couldn't stand it and when he got up beside me, making a lot of exhaust noise, I punched it and left him with a silly grin on his face. By the time I was at 75 mph I just punched cruise and he never ever came up on me for the rest of my trip until I got off of the highway. This LBZ is a big step up from my '98 6.5. Smiling..............Ed

[caddy527]

I just turned 2000 miles and got 18 mpg on the last tank. No highway but some 50mph stretches. I put in Amsoil at 1600 engine and rear. Before that I was in the 16 - 17 range. Don't know if it's the oil or the truck breaking in but I'm not complaining.

[FBJR]

I have noticed the DIC is about 1 MPG under too. Getting about 15.8 on the first tank.

Makes me wonder how far off the speedo is to start?

Just got the Diablo and did the 65 HP tune with corrected tire dia of 33 inches. On the freeway it said I was going 40 when it was really about 65. Then got a brake warning for gosh sakes!!

But I could really feel the diff

Going to reset tonite using tire size vs dia and see if it takes and the code goes away.

FB

[EdHale]

I just got home after a 500 mile weekend trip. The first half of the trip was all highway at 75 mph, removed a 7000 lb boat from the water and towed it 2 miles to a gas station for fuel, then two miles back to the launch. The rest of the trip was at 70 mph home. averaged 19.0 mpg for the entire trip. Total miles on my 06 LBZ right now is 3,300. Ed

No towing except for the 4 miles with the boat.

[cowboywildbill]

Filled up and did a short empty non-towing " semi Highway trip" Some stop and go on a four lane Highway a few lights toward the end. About 135 miles round trip, the computer said we were getting 19.4 at one point. It mostly was saying average of 17.4 while we were at 55 to 65 mph. It seems to be getting better and we only have 1300 miles on it so far.I did an oil and filter change at 1,000 miles Rotella 15w40. I will go with synthetic Rotella after a few more oil changes. I'll post again after I do the math on the last trip. I think maybe about a 16 mpg overall so far best guess.

[Docklobster]

Just returned from my first 1000 mile trip. 1500 miles on the engine now. Ran the AC the entire way, truck is stock. DIC read 11.2 MPG towing my loaded trailer ~9000lbs. Basically southern CA over the grapevine to monterey and back, AVG speed 55 to 60mph.

The MPG did drop a little when I smacked a cow returning over the grapevine!! Truck didn't get a scratch but the trailer has some damage. Cow didn't fare too well, but I was the second person to hit him... Shocks bottomed out but I don't "think" anything was damaged we hit hard, I'm going to the dealer this week to double check everything...

[soot]

I'm starting to think that you need to get 25k+ miles on a Duramax to get consistantly good fuel economy (my '04 LB7 was the same). I was stuck in that 18.5 to 19.2 range for a long time (this is on long Interstate drives), but this past week, I've been getting 20+ mpg with ~26k on my LBZ. Monday I got 20.42 mpg & today I got 20.07, both 300+ mile trips at 70+ mph, hand calculated & using my GPS to track total miles.

Not that I wasn't impressed before, but I'm REALLY starting to like this truck.

[cowboywildbill]

Just did the math after our little trip, we had some stop and go Ranch errand type stuff and a little idle time. The average was 15.9 mpg. Still only 1400 miles on truck. We are happy so far.

[farmerpatrick]

2500 HD 4WD.. extended cab. allison. all power . getting 14.2 on hwy. 9000 miles. Just bought truck. What's wrong with mine? No lead foot here.