i am thinking of buying one of these with the allison trans. i was wondering if any body knows what kinda gas millage these get and if there are any known problems for this year especially since it was the first year for the allison any help would be appreciated

 

eroc33... There were a number of small issues with the '01 trucks. There were some Allison software updates, resulting from software glitches where the truck would go into limp-home mode for no reason. The original in-pan filters caused a pump pickup problem, where when you step on the gas quickly after coming to a stop, it would seem like the trans is in neutral until the pump picked fluid up, then it would jerk forward. The original crankshaft position sensors and camshaft sensors were flaky and most have been replaced by now.

Chevy has been great about correcting all of those small problems that I had.

BTW... you might pose the same question on the DieselPlace forum. They have a section on GM gas trucks, and a huge section on Allison trans. You should get lots of feedback there.

 

what kind of millage do you think i might get if i had the pcm tuned

 

We usually get on average 2 to 5 mpg better from our performance tunes, we can add anywhere from 30 to over 200 hp and tq depending on what you use the truck for and what you want. We can make the tranny shift right, firmer shifts, and make the tow/haul button a RACE button which will be like getting two tunes, a better running one and a full race one when you hit the button.

Right now we have a discount for the members of Truck Forums of $75 off, but that will be comming to an end soon. Let me know when you are ready to order or if you have any more questions feel free to ask.

 

200hp ? on a gas engine

that tow/haul race button would be pretty cool