2003 miles per gallon ?

[bullet2110]

I have a'03 with 4800 miles on it and have done no pulling. My instrument panel has never read more than 15.0 mpg and now has dropped to 14.8 mpg
Can anyone else share how many mpg you are getting with the '03? I really thought it would do better than this.

Thanks.....Mark

[britannic]

Right now I have a 2003 CC/SB driven mainly by my wife; we're getting 14.8 as well. Everything on the truck is stock and the average journey is 20 miles between stops, which involves driving up and down steep grades from 2600' to 21' altitude.

[ 01-30-2003: Message edited by: britannic ]</p>

[BKColeman]

I've got almost 1000 miles on my 2003 2500HD crew. I've filled it up 3 times. The first tank was 15.7mpg. The second fillup was 16.8mpg. The third was 17.6. So for the first 1000 miles I'm averaging 16.7mpg.

I've been keeping a spreadsheet upto date at each fill up so I can compare to my Ford PSD. It averaged just over 18mpg empty. I'm hoping the Duramax improves slightly over what I'm now getting.

So far the computer keeps getting more accurate too. The first tank it was reporting 1.1mpg too low. The latest was just 0.2 short of what I calculated.

--Brad

[hogbody]

I have about 1400 miles on my 2003, cc/allison/camper shell. Live in Oregon on the west side where it has been unseasonably warm. 35-55 degrees.

I am averaging 20 on the frwy. with cruise set betweet 65-70. Combo intown and frwy mileage has been between 17-18.

No towing as of yet.

I am very easy on the pedal and have used the instantaneous mileage display to get the most out of the truck from a stop. It seems that if you accelerate moderately up to 2000 rpm and it shifts keep the rpms at around 1800 up to the speed you want to go.

Used to drive a gas truck with a vacum guage which gave excellent mileage.

Larry

[bullet2110]

Brad....
That's the kind of numbers I was hoping for. Not sure why mine is low. I'm just trying to get some idea if something is wrong or not.

Thanks again

[AlanL]

My '03 has 3200 miles on it and I'm just starting to see an improvement in mileage.

For the first 1000 miles I got about 16 mpg and I was driving very conservatively. Now I'm back to driving at 80 mph alot and I've been getting between 13 and 15 MPG. I know I've got a lead foot, although I haven't been drag racing with the truck by any means.

After a 700 + mile tow this past weekend, and an oil change where they reset the light, I've noticed that the truck seems to have more power and is getting better milage. I filled up yesterday and I was getting 19 on the highway and overall average I'm up to around 16 which has included some warm up time and some time in traffic.

Perhaps the tow helped break in the motor, or the initial reset of the oil change light set off something in the computer.

-Al

[jjackson]

I have about 4,200 on my '03. Mainly used to pull my 5th wheel. Last trip out got just under 12MPG w/a 33 Ft 13K 5'r. Got right at 18 the last time I checked it when not towing.

I've heard also that the D'max continues to improve up to around 20K.?

John

[4x4man]

I am approaching 1,500 miles and my mileage is going up. First two tanks were in the 15mpg range with mostly all in town driving. The third tank gave me just over 16mpg and included a 40 mile tow of our 10k 5er just to see how she'd do... :D
Sorry I don't have exact numbers for each tank of fuel as I really don't keep track. I just do the math at the pump, then smile as I am getting WAY better mileage then my 01 8.1L.

By the way just filled up a couple of days ago and yielded 17.05mpg!! Keeps getting better all the time and the computer seems to only be about .2 to .5 mpg off, not too shabby....

Good luck,
Bob

[bullet2110]

Thanks for all the input.

....Mark

[SoCalDMAX]

2003mpg is a bit unrealistic, IMHO. ;)

I'm pretty happy with 16 - 17mpg, especially with this kind of power underfoot.

Are you guys sure you can trust the mpg readings from that thing? Is anybody backing it up with actual calculations?

Regards, Steve

[HDLD]

I tracked my mileage very accurately for the first 10k. It was pretty much identical to the DIC so I got lazy and stopped. You're not going to get the best figures in the winter.

What I find is that being REALLY warmed up seems to assist a little in the mpg, esp. for faster hwy. speeds and that running, esp. accelerating when cold is extremely punative.

If you kept it at about 1900 rpm for a full tank on the highway, on cruise, when the temps are above 32

[matt-max]

not sure what i'm doing different but...

over the life of my truck (6500ish miles) i've gotten 18.4.

with michelin265s at 80psi, combined city/highway and some extended idling, no towing.

at 65 mph indicated it gets 21.7 mpg average and does not drip more than .5 mpg up to about 73mph.

and i drive with juice on 4 most of the time. i think that's worth at least 1 mpg.

on my 2001 i never really got above high 18's and usually averaged around 16.5 or so all together.

matt

[Dmaxin]

I have about 9000 on my 03 and i am getting 16.5 to 17.5 in the city and about 20 to 21 if i stay on the highway and keep it under 70. I use my own calculations every fill up and the computer seems to be within .5mpg

[KISMIF]

I have 9,000 on my 03 D/A CC/SB.
No towing yet.

City 15.5-16.5

Commuter 16-17.5

Freeway trips:
San Diego to Texas and back 3500mi 20-21.5

San Diego to Phoenix and back 1500mi 19-20

DIC & Calculations also within .5

-KISMIF

[ski]

My DIC is within .5 mpg as well. From day one and 9 miles, a 290 mile round trip avg'd 17.1. 7900 miles later, I am averaging 18 - 18.5. My hiway miles are the same due to 75 MPH speed limit. In town avg's 17.8 with mixed crusing and getting on it. #2 all the time, somewhat mild climate. 14 seems very low, hope it improves.

BTW, I have towed a 3000 lb trailer into the mountains (4000 feet to 10000) and averaged 15.2

[SamIAM]

1900 on mine and only drive 3 miles to work and getting 16. I got 20 driving 73mph and dropped pretty good at 85mph to 15. I have not towed yet since the boat doesn't move in the winter.

[Seattle Steve]

3000 miles and have seen recent improvements of about 1 MPG. I'm now getting 20 MPG with combo city and 65 MPH highway driving. The speedo is 1% slow according to my GPS and overall the DIC registers about 1 MPG below what I get from calculations mostly due to using more fuel than shown on the DIC. No towing yet. Note that I have the ZF6 which seems to help some since I tend to keep it under 2000 RPM's. I have been running Stanadyne additive since the 1st tank.

[Husker Fan]

10,000+ miles on mine

When cruising at 55, I'll get around 23 average (Really, I've seen this plenty of times).

When combined with city driving, I'll average 18 to 19.

When doing about 75 on the interstate, I'll average about 16 to 17.

Pulling a boat or 4,000# enclosed bumper trailer on the interstate (75 MPH), I'll get around 12.

Pulling my gooseneck unloaded, I'll get around 12.

Pulling the goosenect loaded (About 14,000 #s depending on the cargo), I'll get around 10.

Hope that helps

[jjackson]

The 2003 MPG numbers I indicated earlier in this post, i.e.,
(I have about 4,200 on my '03. Mainly used to pull my 5th wheel. Last trip out got just under 12MPG w/a 33 Ft 13K 5'r. Got right at 18 the last time I checked it when not towing.)

were a result of "actual" hand calculations, and compensating for oversized tires.

John