My (new to me) 2006 CCSB 4x4 LBZ that I bought a few months ago has me stumped. Driving very delicately unloaded, I am getting amazing fuel mileage even with 285's. The truck seems to have a ton of power, but never having one prior to this to compare to makes it difficult to know any different. A friend who has an LB7 that seems to work very well says he thinks my truck may have a tune installed. Is it possible the previous owner installed a tune and didn't remove it before trading it in? And is there any way for me to find out if the truck has a different tune than stock? Thanks.

I don't know about the tune, but I would like to know what kind of mileage you are getting. I'm seeing 18~20 depending on how I drive.

I'm almost afraid to say the mileage I'm getting because people will not likely believe it. I live in Canada so I check by doing a Litres per 100 Km's calculation. I drove 547Km's (and added 7.5% for my 285 tires which I have verified with my GPS that the speedo is out by approx. 5 MPH at 60 MPH) for a total of 588 Km's and filled it to the same place in the neck that I always do and used 52.9 Litres. Calculating it out I got a fuel consumption of 9 Litres used to 588 Km's driven. That translates out to 26 US MPG's. That was a mixture of 70% hiway and 30% city driving (all granny like mind you). Even worse case scenario if I use the indicated 547 Kms. it still works out to 24.25 Mpg. Flame away!!! But that is what I got.

I'm almost afraid to say the mileage I'm getting because people will not likely believe it. I live in Canada so I check by doing a Litres per 100 Km's calculation. I drove 547Km's (and added 7.5% for my 285 tires which I have verified with my GPS that the speedo is out by approx. 5 MPH at 60 MPH) for a total of 588 Km's and filled it to the same place in the neck that I always do and used 52.9 Litres. Calculating it out I got a fuel consumption of 9 Litres used to 588 Km's driven. That translates out to 26 US MPG's. That was a mixture of 70% hiway and 30% city driving (all granny like mind you). Even worse case scenario if I use the indicated 547 Kms. it still works out to 24.25 Mpg. Flame away!!! But that is what I got.

It may have been tuned by Wester Garage if it came from Canada, he tuned my 2007 LBZ and I get a round 22 MPG. on the road if you keep it under 65 mph. He reworks the EMC it makes a huge difference in power and mileage.

No I picked this truck up in Alabama back in January. Alot of the driving was at about 55-60 MPH as the speed limit on the only road I use to get to work is 50 MPH.

No I picked this truck up in Alabama back in January. Alot of the driving was at about 55-60 MPH as the speed limit on the only road I use to get to work is 50 MPH.
That would explain the high mileage some. I have seen 22.5 on the DIC right after refuel and driving 50-55 on a longback road for 15-20 miles.

I filled up last night for $101 :eek: 4.799/gal.
The mileage I got from the tank was 18.8 mpg.
I drive a lot of highway @ 65mph.
I am sure if I slowed down I come get better mileage but then I would have to worry about getting rear ended. :rolleyes:

At 4.79 Gal I would fill up there anytime!! Here where I'm at, it's 1.429/Litre which works out to 5.41 Gal and I don't see an end in sight. The gas station attendant this morning said that gas went down and the diesel went up all last night.

My (new to me) 2006 CCSB 4x4 LBZ that I bought a few months ago has me stumped. Driving very delicately unloaded, I am getting amazing fuel mileage even with 285's. The truck seems to have a ton of power, but never having one prior to this to compare to makes it difficult to know any different. A friend who has an LB7 that seems to work very well says he thinks my truck may have a tune installed. Is it possible the previous owner installed a tune and didn't remove it before trading it in? And is there any way for me to find out if the truck has a different tune than stock? Thanks.
have you been drving a prius lately? :lol:

I'm almost afraid to say the mileage I'm getting because people will not likely believe it.

I know exactly how you feel, but it is entirely possible with the stock tune. I get similar mileage, sometimes even better. Don't know why my mileage is so good, while others get poor results - just seems that these trucks vary quite a bit.

I would like to ride with the SOB that getting 28 mpg. Just so they can prove it to me.

I know exactly how you feel, but it is entirely possible with the stock tune. I get similar mileage, sometimes even better. Don't know why my mileage is so good, while others get poor results - just seems that these trucks vary quite a bit.


I think it has more to do with driving style and where you drive then anything else. Most people like to run 70+mph on the highways. That isn't good. I run 65mph and today driving home I tried 55mph which when cal the fuel used and the miles traveled came out to about 23mpg.

What surprised me the most is when I looked in the mirror to see how may other cars were following me. 3 cars a 1 truck. :eek:

It might but its hard to tell would have to drive the truck!

I know exactly how you feel, but it is entirely possible with the stock tune. I get similar mileage, sometimes even better. Don't know why my mileage is so good, while others get poor results - just seems that these trucks vary quite a bit.

x2 except I dont have a stock truck. Im on 35s with hummer wheels and a ppe on 225 and get close to 22 on the highway hand calculated. Thats better than both cummins that I had.

always heard the slower you go the lower the rpm and the less your in the turbo which helps alot on mpg. altitude had an affect on by 04 ram. something to think about since the truck came from down south

I know exactly how you feel, but it is entirely possible with the stock tune. I get similar mileage, sometimes even better. Don't know why my mileage is so good, while others get poor results - just seems that these trucks vary quite a bit.


Yes they vary quite a bit I drive like a insane grandpa and barely hit the gas and keep the rpm's so low you'd think the truck wasn't even running but the most i've ever seen is 17:mad: how the heck is that possible I just don't get:(

I get decent fuel mileage, but I am a litlle skeptical of 26-28mpg's! I would bet that the ECM was not recalibrated for the 285's. Get a hold of a GPS, and check your odometer and speedometer to see if they are accurate.

I have gotten 21-22 on trips keeping the speed around 65-70 and the tach below 1800. Driving habits make i big difference. A fella i know used to get up to 27mpg out of his Cummins with a stick so that kind of milage is obtainable, just havnet heard of it from a D-max/auto trans.

I get decent fuel mileage, but I am a litlle skeptical of 26-28mpg's! I would bet that the ECM was not recalibrated for the 285's. Get a hold of a GPS, and check your odometer and speedometer to see if they are accurate.

Believe me, I understand your skepticism. That's why I was reluctant to even ask the question in the first place. I know for a fact that the speedo/odo are inaccurate based on my GPS. From what I can tell I'm reading about 7% low in terms of speed/distance travelled. I factored that into my hand calc's to get the true mileage readings. Maybe the biggest factor is that most of the driving was done at about 50-55 Mph?

Not here to start a "my truck is better than yours" type of thread. I was just currious to know if maybe there was a possibility that there was a program in the truck that might be helping the fuel mileage out??

Thanks to everyone for their help and insight.

I am also in Canada (Saskatchewan to be exact), so I am using Imperial gallons (20 % larger than U.S. gallon) when hand calculating my mileage. Liters per kilometer don't mean a damn thing to me-very old school in that regard. On the highway, driving at 67 MPH (or 108 KPH verified by GPS-speed limit on 2 lane highways here is 100 KPH or about 62 MPH ),I quite regularly get 21 to about 21.5 miles per gallon in the summer. I have on many occasions seen the DIC indicate mileage as high as 24 to sometimes 26 MPG (adding 20% to indicated average miles per U.S. gallon-DIC does not do computations for Imperial gallons). This higher than usual indicated average MPG happens where the terrain and wind combine to allow the truck to run easy. I realize that the DIC is not totally accurate, but will be in the ballpark.If I could stand driving any slower than I do, I know that my average MPG would likely be some what better, but driving 50-55 MPH over the long stretches between places here doesn't appeal to me.I do have records of every drop of fuel and the mileage on the truck at the time it was put in the tank since I bought this truck in 2006,so can back up my claims.My $.02 worth.