New 2011 GMC 3500 HD Crew Cab SB, Single Wheel

[klash]

We purchased our truck back in August, and right now we are in Patterson, CA at the Kit Fox RV Park. We left home on the 14th of November, 2010 and we now have 1,000 miles of towing. The truck has a total of 3,500 miles on it.
All the worries we had about hooking up to our 2007 Montana, 2955RL had not happened.
With the stuff that my dear wife loaded on board, the back end of the truck went down about 1". There is at least 6" of clearance above the back corner of the truck box when on the level ground. Of course during some turns in and out of gas stations, it will be somewhat less.
The truck and trailer are about as close to perfectly level as one could ever want. When we
are traveling like we are right now, we usually stay hooked up, and then all we have to do is level from side to side.
To date our best mileage has been 14.6 mpg and keep in mind that is on the Canadian gallon which is slightly bigger than the US gallon. The lowest was the first day when we transited highway 101 along the Puget Sound, in the hills and in the pouring rain.
I have tried driving with the Allison in full auto, and in cruise and just let the most
wonderful engine in the world work with the best transmission in the world. Smooth as silk, and I apologize to anyone I may have passed going up some of the 6 and 7% grades.
It wasn't my fault, the truck just wanted to keep on going.
Gears 5 and 6 are both different ratio over drives, and pulling 12,000 lbs, the transmission will remain in 6th in cruise control and not shift up and down. When approaching an incline in full automatic mode and in cruise, sometimes the transmission will drop down two gears and then it handles most mountains in 4th.
I also tried driving in the manual mode and then played around with the tap up and tap down feature. When I notice a slight decrease in RPM, I would tap down to 5th, and as the incline increased I would tap down into 4th. While driving in this mode, I also stayed
in cruise. When I reached the top I would then tap up to 5th and then 6th. Handling the transmission in this matter the shifts were so quiet and smooth my wife said she couldn't even tell when I was shifting. Still not too sure which method of shifting will give me the best mileage.
As a point of interest while driving at a continuous 55 mph, the speed we always drive at, with the cruise control on, the engine RPM is at 1,350.
Last but not least is the new variable vane exhaust brake incorporated into the turbo. Our traveling friends have a 30 foot Cardinal and he pulls with a 2004 GMC, 2500HD, and he was surprised that when he was following me that I wasn't using the brakes coming down the 6 and 7% grades. No aniety, no sweat about having to use the brakes to take some of the speed off. I also use the cruise control coming down the hills.
This morning when we left Corning, CA the average mileage on the Drivers Information Centre started out at 9.3 mpg, and it then slowly went up to 14.5, all of a sudden on perfectly flat land, no wind, the numbers started to drop down to 11.0 mpg. I think this is the first time I have actually witnessed the new Diesel Particulate Filter going through the
regen (burn out) process as controlled by the Engine Control Module. According to the info I have read on line, this process will take about 15 minutes and burn up about 1/2 a
US gallon of diesel. After a run of 215 miles today, our mileage was down to just 12, still not to shabby for a truck with 397 HP and 765 ft/lbs of torque and pulling 12,000 lbs.
As of this date we haven't found anything about the new truck that we don't like.

[CamillaMichael]

Good for you! Sounds like you and your truck are a perfect match...hopefully it will continue to serve you well on all of your travels.

[CORattler]

Ahhh, a man and his truck! I'm glad you are enjoying the truck and wish you many trouble free miles. Thanks for the report. A valuable item for those considering a similar purchase.

[thor]

yes thanks for the report. i just purchased a 2011 dually chev and have yet to haul long distance .the truck only has 300 miles on it. hope to be a lucky and satisfied as you are with yours. goodluck and enjoy

[swanny]

Yes that Dmax Allison combo is a sweet thing. Over the summer I gave my truck a workout on route 6 in Maine, I was very impressed. Good luck and safe travels.

kevin

[Illini Trekker]

Thanks for the report, pulling the 2955RL is a breeze for my truck and with the increase in HP with your I can see you eating up those hills. You talked about watching as you turn are you close to the bed side rails? I added the TrailAir with GlideRide and needed to raise my hitch to compensate the add length of the hitch. Enjoy the new ride when I get my old paint wore out I'll be moving into the same truck!

[rames14]

We had a 2004 2500 HD and now a 2008 3500 HD. That 2011 sounds sweet, but I only have 50k on the '08. I guess I'll have to live vicariously through my fellow MOCers. Good luck and safe travels.

[drknapp]

Sure sounds like a nice truck!

That exhaust brake makes me green with envy!

[Art-n-Marge]

With the 5er towing level and having 6" truck bed rail to trailer underhang clearance, those are good numbers and you should not have any problems with the majority of dips, bumps, humps or hills. That is typically what all the specialists say. I have 7" clearance and I am only slightly nose high, but don't want to change it because I think then I would be messed up and be nose down so I have left it alone.

It was great reading your testimonial. Another happy rig on the road!!!