23+ MPG and loving it!

[Camstyn]

Two weeks ago I bought this truck, a 03 Chevy 2500HD 4x4, Dmax/ZF6spd, fully loaded. I bought it to replace my '02 6.0 gasser due to poor fuel mileage and that lovely cold start knock. Anywho, I drive a ~300 mile trip 6 days a week, thats my job.. Usually on Fridays the load is very light so I've been using the pickup. The first time I did the trip, which was still on the first tank of fuel, I got 23.7mpg. Truck was stock with the exception of the K&N filter. I had the truck straight-piped and did the run last Friday, got 23.0mpg. I just got home again from the trip and got 23.1mpg this time. I'm a hillbilly canuck but I know the difference between US gallons and imperial gallons, and the DIC on the truck measures US gallons, I verified it. Someone said in a different thread that I was the first member on the site to get better than 23mpg, what an honor, you won't hear me complain. The total average MPG on the truck, currently at 1524 miles, is 21.1mpg.. This includes romping around town quite a bit and lots of idle time. I took some digital pics of the dash for photographic proof, as I know that unusually high mileage numbers are hard to believe and so many people exaggerate them. Here you go. :D

Sorry for the poor picture quality, it was getting dark out, I had to turn the flash off and the display is rather bright, so there is a lot of noise on the actual readings.

I'll make links to save bandwidth..

The truck (http://members.shaw.ca/camstyn/supertruck.jpg)
Odometer (http://members.shaw.ca/camstyn/odometer.jpg)
Overall miles per gallon (http://members.shaw.ca/camstyn/avgmpg.jpg)
Business trip miles (http://members.shaw.ca/camstyn/miles.jpg)
Business trip gallons consumed (http://members.shaw.ca/camstyn/gallons.jpg)
Business trip miles per gallon (http://members.shaw.ca/camstyn/mpg.jpg)
Business trip miles per hour (http://members.shaw.ca/camstyn/mph.jpg)
Business trip kilometers (http://members.shaw.ca/camstyn/kilometers.jpg)
Business trip liters consumed (http://members.shaw.ca/camstyn/liters.jpg)
Average liters per kilometer (http://members.shaw.ca/camstyn/lpkm.jpg)
Average kilometers per hour (http://members.shaw.ca/camstyn/kmph.jpg)

Did I say how much I love this truck? :D

[jbplock]

Camstyn,

Congratulations on your new Dmax and those excellent mileage numbers! :D A friend of mine has a 2003 with the ZF and he seems to get better mileage than I do with the Allison. My best mileage to date is 20.5mpg on trip doing 65-70mph (calculated the old fashioned way by dividing miles driven between fill-ups by gallons read from the pump as I found that the mileage computer on my truck reads on the optimistic side by 1 or 2 mpg). One suggestion is to use the personal trip odometer to manually keep track of mileage between fill-ups and the business trip odometer to track miles between oil changes.
smile.gif

[dmaxalliTech]

Hey, where is the rest of your truck?? Some of your gain could be due to the fact your a good bit lighter then most of us, C/C and Excabs are the norm usually, reg cabs are a bit rarer. You have stock tires on?

[DuramaxDicko]

Camstyn

just a suggestion, you may want to take the total 1524 miles (or whatever it is now) and take all the fuel fill ups since truck was new (from your own logs or receipts) and divide to get an average of what kind of mileage your getting.
I know on my truck, the DIC lies, I've seen the mileage go to 29.5 to the us gal.. that would never happen, but it did show it once and most of the time shows in the range of 21, but when I do the math myself, my average is around 15.. which is expected... if I use the DIC, I think I get DIC.

take care
dick

[HD-Nate]

Originally posted by dmaxalliTech:
Hey, where is the rest of your truck?? :eek: :D :D

[Camstyn]

Originally posted by DuramaxDicko:
Camstyn
just a suggestion, you may want to take the total 1524 miles (or whatever it is now) and take all the fuel fill ups since truck was new (from your own logs or receipts) and divide to get an average of what kind of mileage your getting.
I know on my truck, the DIC lies, I've seen the mileage go to 29.5 to the us gal.. that would never happen, but it did show it once and most of the time shows in the range of 21, but when I do the math myself, my average is around 15.. which is expected... if I use the DIC, I think I get DIC.
take care
dick I haven't kept my receipts for the previous two fillups, so I don't figure that out. My last tank (671 miles) my DIC said that I got 21.3MPG. I did the math manually at the pump and it worked out to 20.7MPG. I don't know which is more accurate, I guess I'll have to keep monitoring it.

[WillowCreekStable]

My neighbor's display in his '03 is always a bit optimistic when compared to actual calculations. Seems the DIC was designed by the marketing department.

[DMAX Daddy]

My D.I.C. estimates are always bigger than reality :D