2008 gmc dually info

Halmfamily wrote:

Lantley wrote:

Halmfamily wrote:
That's a great truck, see my sig.
This truck truck does not use DEF but runs a regen cycle every 500 to 800 miles depending on your driving. I'm averaging 16 mpg bobtailed and 8.5 to 9 towing my 42' fifth wheel. You'll notice a drop in fuel economy when the regen cycle is running. I have a Scan Gauge II on my truck and can tell when the regen is in progress. You don't want to shut the truck off when its running the regen. The turbo pressure will be low when it running the regen and egt temps high. Run the truck hard and it will take care of you.

It's an awesome truck, reliable and powerful. I'd snatch it up because they are hard to find in my area, at least.

The low towing MPG speaks to the issues of the early DPF trucks.
While they are OK trucks. The 1st generation DPF trucks suffered from poor MPG's. I would prefer a later model year 2011 or newer. DEF was introduced by then. The frames/suspensions were also beefed up and payload ratings where increased.
The manufacturers learned from their mistakes. Diesels of the era were OK. However the next generation was a drastic improvement. Emission technology improved and so did MPG's
I consider the 2008 era the learning curve period when it comes to diesel emissions.I would avoid diesels of this era simply because better emissions technology has produced better more efficient trucks since then.

If I was buying a truck for fuel efficiency I certainly would not have purchased a one ton diesel, maybe a Colorado or similar. This truck is a tool used to haul my fifth wheel so fuel economy is not a primary concern. If your concerned about fuel economy while towing I think your in the wrong hobby. My F350, in sig, got the same mpg towing but 18 bobtailed.

I understand MPG's are not your primary concern. I also understand your truck meets your needs which is really all that matters.
However the pre emissions 2006-2007 trucks will get 11-12 MPG towing and the 2010? and newer DEF trucks will also be in the 11 MPG range. 8-9 MPG's towing maybe typical for trucks of the 2008 era but it is poor for a modern diesel truck.
The fact remains the 2008 era trucks had lower MPG's due to the early generation emissions systems.
If one is in the market for a used diesel truck they can ignore this information or they can factor it into their purchase.