MPG ON 05 2500HD 6.6

[REDTRUCK05]

NEW 2005 2500HD 6.6L WITH 1,400 MILES GETTING 9 MPG PULLING 7500 LBS ON LEVEL ROAD. GETTING 14-15 MPG EMPTY SHOULD I CONCERNED?

[fourtenposi]

I have a new 2005 gmc d/a combo with about 2000 miles on it. I get around 20-21 running down the road about 60 mph and I pull a 8500 pound enclosed trailer and I got around 11.5 running 60 mph. How fast are you running down the road? My fuel economy heads south at anything about that. If you want the best fuel economy try to keep the rpms around 1800 rpms.

[REDTRUCK05]

Originally posted by fourtenposi:
I have a new 2005 gmc d/a combo with about 2000 miles on it. I get around 20-21 running down the road about 60 mph and I pull a 8500 pound enclosed trailer and I got around 11.5 running 60 mph. How fast are you running down the road? My fuel economy heads south at anything about that. If you want the best fuel economy try to keep the rpms around 1800 rpms. RUNNING AT 65-70

[soundrisk]

Hi Gang.... Just got another D/A Crew... Less than 700 miles on it...

Towing an Airstream from Grand Rapids to Oshkosh (through traffic/construction) and pulling hard at 70mph...Averaged 13 mpg according to DIC...

This trailer is 23 feet long, but is heavy at 6400 lbs (rebuilt with real wood interior)...

I expect to get around 18-19 in town (just got to keep from zooming from stoplight to stoplight..)

Hope this helps..

[bamabadboy]

19 MPG at 65 MPH running empty. Drops to about 11 MPG pulling a 7X16 enclosed trailer with two big Harleys.

[Roy W]

I get 11 mpg towing a 9200 lb 32 foot travel trailer at 60 mph, and 17.5 mpg with just the truck at 75 mph. I don't have DIS computer, so these are actual figures.

[stock05hd]

i got about 1100 miles on my 05' 4x2 cc/sb and only getting 14-15 mpg city/hwy with my ac always on here in vegas...
will it get better with more miles?
on hwy i average about 70 mph
45-55 mph city driving
thought it would get better mpg after reading in this fourm.

[Davis]

I have a 2005 2500HD with about 2600 miles on it and average about 15mpg in city ,11.4 mpg towing a 34ft Airstream tri axle travel trailer that weighs about 8500lbs,and I don`t know what the solo hwy mpg is yet. Davis

[jsmiracle]

I have a new 2500HD D/A and I get about 16 mpg in town unloaded and about 10 mpg towing a 9k lb. TT. Oh, yeah.... I have about 2500 mi. on it.

[markrinker]

My new '05 is getting 12 average while trailering loaded and/or empty.

First 'no trailer' trip just yielded a solid 20mpg.

[REDTRUCK05]

TONIGHT WAS THE FIRST TIME I HAD MY TRUCK AND TRAILER ON THE HIGHWAY. I LOCKED THE CRUISE ON 75MPG AND WAS VERY BUMMED WHEN I WATCHED MY MILLAGE DROP TO 7.2MPG! WATCHED THE COMPUTER OVER A 20 MILE STRETCH PULLING 7000LBS. ALL I CAN DO IS COMPARE WITH WHAT I AM USED TOO. I AM READING THESE POSTINGS ON YOUR MPG AND DONT UNDERSTAND HOW YOU ARE HAPPY? LAST WEEK I WAS FORCED TO TRAVEL AT 60-65 WITH TRAILER AND GOT 9.5-10.5MPG, STILL UPSETTING. I ONLY HAVE 1,700 MILES WITH NO CHIP, I HOPE THOSE TWO FACTORS WILL HELP THE END RESULT

[REDTRUCK05]

Originally posted by Roy W:
I get 11 mpg towing a 9200 lb 32 foot travel trailer at 60 mph, and 17.5 mpg with just the truck at 75 mph. I don't have DIS computer, so these are actual figures. 60 MPH? HOW DO YOU TRAVEL 60M ON THE OPEN ROAD WITH OUT GETTING PUSHED OFF?

[markrinker]

75 mph with 7000# in tow? 7-8 mpg sounds about right, especially if there is wind drag on the load being towed.

When towing its speed vs. economy. How much do you want to spend to get there X minutes earlier?

Personally, I have learned to get up earlier in the morning, and slow down.

[rob@rone.ca]

I just bought a Chev 05 3500 srw ext cab long box 9900 gvw 4wd.

First three tanks empty I averaged 13.5 l/100km = 20-21 mpg (imperial) so that would be 17 US mpg. The computer showed about 1 mpg higher averages than the real calculations.

That was combined local and short (100 mi) trip driving with no load. I drive for economy, on Vancouver Island here the speed limits are 90-100 kmh which is about 56-63 mph and I do consistently 5-7 over. There is a steep hill leading up to the house for about 1.5 miles, that drops me way down real quick. The "trip" driving includes quite a few traffic lights going from Nanaimo to Victoria, case anyone knows the area.

With my old 93 reg cab long box 8600 GVW 4wd standard shift 6.5 TD I'd get 23 mpg ( 19-20 US ) in this same kind of driving.

The last tank-full I had my rather heavy S&S camper on top, masde a trip to Long beach - slow winding highway through hills, and the other half local driving - averaged 17.3 l/100 km = 16.6 mpg imperial = (13.8 US)

The old 93 used to haul the camper with 15.8 l/100 km = 18 mpg imp = (15 US )

So for now I would be saying that the efficiency of the engine is about the same as my old one, given the extra weight it's hauling, and the automatic which probably loses some as well.

Definitely higher speeds or going up hills with the camper on suck up the fuel.

Salesman told me mileage should increase as it wears in - service manager said don't count on it.

[dmax lover]

The service manager is wrong. You will typically see mileage increase as the engine breaks in. Takes 5k to 20k miles to break in depending on use.

jeff

[Kennedy]

My 2005 netted approx 11mpg running Loyal WI to MT/ID for TDP Pull Off. This was with 11k in tow and running 75-77mph mosty of the way including the grades:

http://www.thedieselpage.com/features/pulloff05-55.jpg


A few years back I pulled a stack of trailers that KILLED my mpg. 6.8-7.5 was all I could do. I believe that having too little power (this was back in the pressure only type of box days) can also kill mpg severely. This was from Dell Rapids SD toLoyal WI across state hwy's (off the beaten path) and 60 mph was a chore. 0-45mph was easy:

http://www.kennedydiesel.com/photogal/images/Trailer%20stack.jpg

[Jim Brzozowski]

The GN in picture no. 2 looks a lot like mine, probably twice as heavy as your car hauler in picture no 1, but just look at the wind aerodynamics of that stack of trailers. Thats the fuel mileage killer. Wind drag is critical and increases by the square of the speed. Now look at the aerodynamics of your LB7 on the trailer. Major difference.

[rob@rone.ca]

Dmax lover says up to 20K to break in

Anyone know how long to wear out?

Has anyone driven one over 300 k miles? If so, what (if any) major repairs to engine, tranny, or truck?

Maybe this should have been a new thread?

[Kennedy]

The car trailer LOOKS light, but specs at 3300#...

[JoeyD]

Originally posted by kennedy:
The car trailer LOOKS light, but specs at 3300#... I thought the lower tag weight was the main advantage to have the aluminum vs steel? It's hard to believe that it weights over 2000lbs from the picture. What GVW is it?

[REDTRUCK05]

Originally posted by Mark Rinker:
75 mph with 7000# in tow? 7-8 mpg sounds about right, especially if there is wind drag on the load being towed.

When towing its speed vs. economy. How much do you want to spend to get there X minutes earlier?

Personally, I have learned to get up earlier in the morning, and slow down. I am just comparing same weight, speed (70-75) and road as with my 7.3 and am getting 4 mpg less. I now own a new and very expensive chev, for the most part I am enjoying the truck. I honestly have no reason to say anything untrue about either it or my Ford (2001 F250 7.3). Just alittle taken by the difference between the two. Not to mention the noisy and costly fan ( takes fuel to drive that much air). I know that they changed the 2006 lly fan assembly so it does not come on near as often or as long. (like the early LB7 and my Ford. Honestly did not mean to offend anyone, just dissapointed with those issues SO FAR. Thanks for your input

[Roy W]

Red Truck (Mine's also Victory Red).......The 60 mph tow was all on secondary roads. I haven't towed on the interstate yet.I'll be going to the Smoky Mtns in October and that will be my first interstate tow.

[REDTRUCK05]

Originally posted by Roy W:
Red Truck (Mine's also Victory Red).......The 60 mph tow was all on secondary roads. I haven't towed on the interstate yet.I'll be going to the Smoky Mtns in October and that will be my first interstate tow. Have a great vacation, well earned I'm sure! Let us know what your results r!

[SHOPMAN426]

I just read this topic for the first time. I figured it didn't concern me because I own a 2002. From what I am reading it sounds that this little fancy milage computer in these newer models is not believable. I think you need to do it the old fashion way, stick the nozzle in and don't stop until you see the fuel resting at the top. Then you will get real world numbers. I pull 9000 lbs. of fifth wheel and average anywhere between 8.9 to 11.7 mpg, empty the best I have ever seen was 17.6 mpg. I've got just under 20k on the truck, you guys with less than a 1k need to park the computer for a while.

Kennedy's numbers look spot on for the load he's pull-in. Are you using the computer or doing the math at the pump?

Shopman426,
Mike. tongue.gif tongue.gif tongue.gif

[Kennedy]

Originally posted by Joey D:
</font><blockquote>quote:</font><hr />Originally posted by kennedy:
The car trailer LOOKS light, but specs at 3300#... I thought the lower tag weight was the main advantage to have the aluminum vs steel? It's hard to believe that it weights over 2000lbs from the picture. What GVW is it? </font>[/QUOTE]25' long, 10k GVW. I was going for finish appearance/maintenance rather than weight.

[JoeyD]

Originally posted by REDTRUCK05:
</font><blockquote>quote:</font><hr />Originally posted by Mark Rinker:
75 mph with 7000# in tow? 7-8 mpg sounds about right, especially if there is wind drag on the load being towed.

When towing its speed vs. economy. How much do you want to spend to get there X minutes earlier?

Personally, I have learned to get up earlier in the morning, and slow down. I am just comparing same weight, speed (70-75) and road as with my 7.3 and am getting 4 mpg less. I now own a new and very expensive chev, for the most part I am enjoying the truck. I honestly have no reason to say anything untrue about either it or my Ford (2001 F250 7.3). Just alittle taken by the difference between the two. Not to mention the noisy and costly fan ( takes fuel to drive that much air). I know that they changed the 2006 lly fan assembly so it does not come on near as often or as long. (like the early LB7 and my Ford. Honestly did not mean to offend anyone, just dissapointed with those issues SO FAR. Thanks for your input </font>[/QUOTE]My brother and I just did a road trip to VT and he towed up there , 25' GN with a 5200lb truck on it and he got just under 8 mpg. He ran 70-75 and he has an lifted 01 with the 8.1.
I hauled the same load back and averaged 12 running 65-70 with the same load. I would give it some time to put some miles on it unless it's not running good. I would expect better than what your getting thats for sure.