My question is this, How happy are any of you out there that have the 8.1 and the Allison trans. in a 3500 dually. How does is pull with a full load in the bed compared to a diesel dually set up the same way? How about mpg towing? Does 2wd compared to 4wd really make that much difference in mpg? I currently have the 8.1 and Allison setup in my 2002 2500Hd 2wd crewcab and I pull a 13,000# fifth wheel with a pin weight of 2100#. Im looking at a 2002 3500 crewcab dually 2wd with the 8.1 and allison transmission, basically same truck as what I have now just a dually. The gvw difference is 9200# vs 11,400# which gives me alot more payoad capacity and also the stability of two more wheels in back, but I'm just wondering how much worse my mpg will be, and if it will be even more strapped for power than what I am now? Any comments will be appreciated thanks, Marc

grant I am an 8.1 supporter, but you see that 8100 vortec was derated to 330hp and 450 ftlb. Pure towing go with the dmax, at least they up-rate that engine.

Not sure if this would help, but in my experience I never ever have seen or heard of a 3500 dually truck with 8.1L gasser. Probably would be rare to see it.

Thanks for the replies both of you. Hammer I did see the new ratings you refer to. I do love my 8.1 but I'm just not sure how it would do with the added weight of the truck and extra gear added to the overall towing ability, and being able to step on it and be able to pass with ease and run 65-70 mph. Also I can't imagine getting worse mileage than what I do now towing..lol.


Contrary to what you might think wxmn the 8.1 is pretty common. I have looked at 4 used ones 3-2002's and 1-2003, and also two brand new 2004's all having 8.1's in them and found at least 6 more brand new ones online. 3500's come either gas or diesel it's your choice nothing rare about it.


Thanks again, Marc

Well, that's surprising because it seems that every time I see a 3500 dually passing by me, it has a Duramax badge on the door. http://www.dieselplace.com/forum/smileys/Embarrased.gif

The Duramax may be more common, but you can get any othe the three engines offered in the 3500 duallies. The 6.0L is the standard engine for the 3/4 and 1 ton trucks though. Most people that go for a dually are going to get either the 8.1L or the D-Max. D-Max probably being the more popular of the two...