Well I just took the 3500 crew dually to florida and what a dissapointment!!!:help: I weighed in at a cat scale and had a 20500lb GCW. I averaged only 8.35 MPG's towing. Avg speed was 65~68 MPH. I checked the dic and hand calculated and they were within .5 MPG. In Florida we averaged 13.23 around town empty. I have had the reflash within the last 3 weeks. I have about 7k on the spedo. I ran Stanadyne on the way down and none on the way back. MPG seemed to be no different. I am at a loss for words. What should I do next. Compared to my LB7 I tossed $200 out the window. Would an exhaust system help!! :confused: Somebody tell me what to do!!! I talked to about 20 other trailer haulers and I had the worst MPG. I saw a guy at the campground with a new Ford and his avg. was 15 MPG. Same trailer weight!!

I was getting bad mpg towing with my 610 cummins engine. I tried a mix of 16 oz power service and 8 oz Marvel Mystery Oil per fill up. Mileage increased A little over 2 mpg along with quieter smoother engine. I wont go without it now!

The only thing I have found that helps MT is the S&B filter kit with the bottom cut out. I picked up 1-2 mpg with it alone. Loaded I run it and the Edge EZ or the Predator. The LLY mileage is not that good.

The only thing I have found that helps MT is the S&B filter kit with the bottom cut out. I picked up 1-2 mpg with it alone. Loaded I run it and the Edge EZ or the Predator. The LLY mileage is not that good.
what is the S&B filter kit?

Here is a link to the S&B thread

http://dieselplace.com/forum/showthread.php?t=29672&highlight=S%26B+filter

I pulled my equipment trailer(total weight 20,000#) 250 miles (round trip) and got 13 MPG, thought that was good

You guys can call BS on me if ya want, but my Buddy Terry Delong of PRoglassProfinsih In IN helped me put together my truck, and I just went to the C5/C6 bash in bowling grenn KY, My mods are as follows a Airiad Intake system, MBRP front pipe, or down pipe whatever you want to call it, a MBrp exhaust, and a Predator on the #2 tune, crusing at 68 mph to 70mph, I averaged 26.5 the hole way there, I got 590 miles out of the tank before the low fuel light came on, my truck is a 2004.5 GMC siaerra crewcab short bed. I love my truck, and have gotten great gas milage, I use #2 diesel, or my buddy fills me up with off road diesel from his work, I have 21,932 miles on the truck temps outside ranged form 55 to 75. I am happy with my truck like no other if anyone can explain to me why I do so good please tell me, I want to help others get the mileage I get.
This site:ro)

Well I just took the 3500 crew dually to florida and what a dissapointment!!!:help: I weighed in at a cat scale and had a 20500lb GCW. I averaged only 8.35 MPG's towing. Avg speed was 65~68 MPH. I checked the dic and hand calculated and they were within .5 MPG. In Florida we averaged 13.23 around town empty. I have had the reflash within the last 3 weeks. I have about 7k on the spedo. I ran Stanadyne on the way down and none on the way back. MPG seemed to be no different. I am at a loss for words. What should I do next. Compared to my LB7 I tossed $200 out the window. Would an exhaust system help!! :confused: Somebody tell me what to do!!! I talked to about 20 other trailer haulers and I had the worst MPG. I saw a guy at the campground with a new Ford and his avg. was 15 MPG. Same trailer weight!!

First off, you are probably the only person who was reporting honest MPG. How fast were the other guys towing? The guy with Ford :blahblah: was lying if for no other reason than to make a GM owner feel bad.

I got 14.8 mpg on my first towing experience with my new TT, but it only weighs about 6,500 pounds and it is very aerodynamic. I only drove 58 to 60 mph.

And then it seems that conventional wisdom says the D-max really does not break in until 8 to 10 thousand miles.

Seems that always the new guys "hav8" can get better mileage then everyone else can even dream of. Maybe the key would be to go join a new fourm and watch your mileage go to over 25 MPG. As for my towing mileage, I average about 9.5 MPG towing 10,000 pound going about 70 MPH.
Dan

I have an 05 CC dually. Towed 10,000 lbs with 1500 other lbs in the truck bed (Goldwing mc). On the way to Florida, my speed was 59-62 breaking in the new truck. Got 11.5 mpg average.

On the way home with same load, got 10.1 mpg with average speed at 65-66. The last 5 mph cost about 10% more fuel. This makes sense to me because wind drag increases exponenitally above 60 mph.

Paul

I have had 3 LLY's and none of them get consistant double digit mpg towing.

I have about 20,000 on my 2005 GMC 3500 4X4 dually I get approx 17 MPG around town I towed my 29 Foot Layton camper hunting and was getting approx 15 1/2 MPG .

We,ve made one trip to AZ (6500 miles round trip) & one to Florida (3000 or so). We get somewhere between 8&9 mpg. I drive 65-75 depending on conditions. The truck is stock and is one sweet ride compared to my 93 gasser sitting in the yard (5mpg towing). You want mileage buy a Toyota (you won't like it with a 14,000 lb fiver behind it).:)

You guys can call BS on me if ya want, ......... My mods are as follows a ....... and a Predator on the #2 tune, ....... I averaged 26.5 the whole way there, ........ my truck is a 2004.5 GMC siaerra crewcab short bed.

Hav8,

Did you hand calculate the fuel mileage, or are you going by the mileage displayed by the DIC? The Predator is known to distort the computer displayed mpg figure upward by a significant amount. If 26.5 is hand calculated and there are no other factors (tail wind, bad fill, etc), then you have an exceptional truck. I would have expected about 20 mpg.

OK, I'll bite! I call bull **** on this 26.5 mpg! Yeah, my DIC says something crazy like that when using the Predator, but it is obviously skewed due to the programming!

I could run super-duper fuel additive, drive at 50 mph, use no A/C, inflate tires to 80 psi, put a tonneau cover on, and travel only downhill and still not get mileage like that.

I'm not making a personal attack here, I'm just baffled at how this truck could possibly get that kind of mileage in reality.

If it is in fact legit, you should contact GM so that they can learn what happened with your truck so they can let the rest of us in on the secret!

All you guys need to get 26.5 mpg is a 100mph tailwind that's all.

I've talked to a few people with new CTD's and PSD diesels, I mean the emmisions ones like the lly. They all get crapy milage compaired to their predessors. The ford guy is pulling your leg. My freinds uncle told us for years his excursion with a PS in it got 22 miles per gallon on the freeway. He sold it to my friends brother in law. My friend asks, "I'll bet you love that 22 MPG and the guy says huh. He had never seen a stich over 16 since he got it. People say that crap to make you feel like they made the right choice and you did'nt. It's just BS. I put exaust on my lly and also a predetor. I think my milage increase about 2-3 miles per gallon on average, not to mention the smile on my face.

Hand calculated I am very Wrong! I accept all jabs and flames, hand calculated it came out to 23.3. I am sorry to have said other wise. Site still:ro)

Also all I had was maybee 2,000 lbs in the bed not towing anything, once again sorry guys

As previously stated speed makes a difference. The truck seems to get its best mileage under 1900 rpm which is about 63 mpg. Break that and the mileage decreases as the speed increases.

I pull a 38' 5th wheel with a 2500HD; GCW is around 21K. My mileage from Colorado Springs, CO to Mt Rushmore was 10.8 for the trip. I was in the 12s until I got off the Interstate. The rolling hills on the 2 lane changed the average. Coming back from the trip I was in the 8s for the two lane but it increased back to 10.7 for the trip once I got back on the Interstate.

Weather is another major player. My 5er is 13' tall. Driving from Amarillo TX to Colorado I was averaging 6s due to the wind. I could not even pull in OD.

If I can average high 9s low 10s with the weight and height of the load I pull I'm happy. Truck is 03 and completely stock.

Just put on 6000 miles travelling from California to the Yukon towing a 12000 lb travel trailer, Edge on level 2. Overall mileage 12.6 MPG! I used my GPS trip odometer as I have bigger tires. The best I have seen driving MT and with egg's under the throttle was 19.9 MPG