In December, when I first picked up my truck, it had about 6 or 8 miles on it. I drove around for a few days with the DIC displaying "Average MPG". At first it started at about 4 or 5 MPG. It started to get higher and higher numbers as the days went by, but very slowly. I assumed that this was because the truck was new and had no prior history to go on.

I finally peaked out at around 14.2 mpg. I never did the calculating by hand, and I admit I was more than a little envious of the guys who were getting 19 -21. I never reset the average MPG on the DIC because I didn't want to start out at 4 or 5 again. I couldn't believe it, but whether I drove like an old lady or if my foot was pushed thru the floor, I never really varied more than 14.1 to 14.2 MPG.

But then a funny thing happened. I was taking a drive (about 40 miles) to see a friend, and I fueled up just before hitting the highway. On just a whim, I not only reset the odometer back to zero miles, but I reset the average MPG back to zero, too. In less than 5 or 6 miles, the numbers on the DIC were climbing like they had eyes. My truck was registering over 20 mpg. I couldn't believe it and I wondered how this could be.

Then I thought about it for a minute. Before I reset my Average MPG back to zero, it had almost 5,000 miles of history on it. Think about it, if I drove super fast or slow as a snail, it wouldn't affect that previous 5,000 miles of history all that much.

My point is this: there are a lot of people out there thinking they're getting poor mileage, and although in some cases it may be true, in other cases, they may have made the same mistake as me. I now reset my Average MPG back to zero every time I fill up. BTW, when I finally did the hand calculations on that last tank, it was within a half mile per gallon from what the DIC said it was. Not bad. I hope this was of some help...Carmine

The trailer that I tow everyday weighs about 8500 lbs. I get about 10mpg. It sucks. My 7.3 Powerstroke with a 6" lift and 37" got 11. I'm disappointed in the fuel milage. But the truck tows it very well power wise. The suspension is a little soft for a real load.

[quote=Freestylest22;1044112]The trailer that I tow everyday weighs about 8500 lbs. I get about 10mpg. It sucks. My 7.3 Powerstroke with a 6" lift and 37" got 11. I'm disappointed in the fuel milage.

To be honest, my truck is driven empty most of the time. This is my first diesel and I certainly don't claim to be an expert, but from what I've read on this site, bigger tires will hurt your mileage. I see that you upgraded your tire size, but I don't know about the diameter...Carmine

I recently installed the PPE xcelerator on my 06 truck with 37's and an 8" lift. I tow a 26' boat and avg. mileage is 14-15.

On just a whim, I not only reset the odometer back to zero miles, but I reset the average MPG back to zero, too. In less than 5 or 6 miles, the numbers on the DIC were climbing like they had eyes. My truck was registering over 20 mpg. I couldn't believe it and I wondered how this could be.

You reset the odometer? You mean the trip distance?

It'd suck if you went to buy a truck and the guy had 300,000 miles on it and reset it before driving 30,000 miles. It'd be great for trade in though.:lol:

You reset the odometer? You mean the trip distance?

It'd suck if you went to buy a truck and the guy had 300,000 miles on it and reset it before driving 30,000 miles. :lol:

Oops! Did I forget to say trip odometer? Just wait til you get to be my age...Carmine:lol:

Oops! Did I forget to say trip odometer? Just wait til you get to be my age...Carmine:lol:

Did you reset both trip odometers or only one?

You need to reset the gallons used!!! This will also reset the range. Which as I can tell will give you the range based on the MPG... I only have about 1300 miles on mine so Im still trying to figure this out!! :)

Nope.... range is based on the reading on the gauge.

Next time you fuel up, leave the key on (or engine running) and leave the DIC set to "Range" and watch it climb as fuel goes in.

Range is based on the fuel tank reading and some internal MPG average... NOT the one that we can reset. My range was always pretty accurate, maybe a touch optimistic.

Now with the 52 gallon tank, I just double it until I hit 1/4 tank, then I've only got about 100-150 miles left.

Trip odometer settings have nothing to do with either range or MPG calculations.

When I first picked up my LBZ in December the DIC was displaying 3 MPG and I said to myself this is going to suck. The DIC slowly increased as I drove the vehicle until it reached an average of 18.4 MPG, I now have 2500 miles on the truck. This is the life time average and I figure I won't reset the DIC since I allways calculate my milage. I am seeing over 21MPG on most fillups. Thats New Jersey driving 75% rural and suburban. I only have a small toy hauler for my bike 3500lbs, but only towed that twice for a short distance, so I can't really give towing MPG. This is my first diesel and I could'nt be happier with the performance and economy.

vandal,

how did you break your truck in? how fast are you driving to get 21+ mpg? I am about to receive my new 2500HD and would love to get that kind of economy out of her.

Did you reset both trip odometers or only one?
I reset both, although I don't really think it would matter either way, or if I even reset them at all.

If you really want to get into mileage, you can also incorporate the hourmeter into your calculations. I am not sure if I can attach the Excel spread sheet I made, but if you compare the hours to the tank you can also get an idea of your average speed and see how that plays into your mileage. Hopefully I can attach it so you can see what I mean.

I reset both, although I don't really think it would matter either way, or if I even reset them at all.Resetting your Trip Odometer(s) does NOT affect the Average MPG reading at all. When you reset the MPG reading, the computer keeps track of fuel used and miles driven from the point when you reset it. It is done separately from any other display reading. The trip odometer(s) do NOT affect it and neither does the Fuel Used reading. It is a totally separate calculation.

vandal,

how did you break your truck in? how fast are you driving to get 21+ mpg? I am about to receive my new 2500HD and would love to get that kind of economy out of her.

I followed GM's guidelines when I broke the truck in. I fiqured they knew the proper breakin procedures. Iam not an overly aggressive driver anymore, but I do drive 5MPH over the speed limit most times(70MPH being my fastest). I am planning a trip to Las Vegas in June and Iam betting that my my overall MPG will increase.