I was reading the thread on rv.net and just gave me a thought.....I was wondering who all has the ultimate Allison Transmission, and what loads everyone is hauling....and what engine you all have. Duramax or the 8100 .....so to start this off, I have the Duramax and am Towing 22,500 lbs. I currently have 29,250 miles.....I currently have towed 15,000 miles ...I have been averaging right around 9-10 towing and 17-19 city /highway...and 20-21 on teh freeway on longer trips.....so far and all I have to say is that the general finally got it together for drivetrain combination whether it be the 8100 or the duramax and to top it off the Allison....Thanks dmaxster