I finally got some real knowledge! I have a 2007 2500 Mega with a Hemi and 3.73 gears. Dodge dealership in Corpus couldn't answer my questions concerning towing difference between Cummins vs Hemi and RV dealerships are trying to sell me 15,000lb trailers. I specifically asked both places can my current truck tow a 15,000 lb trailer, and they both said yes. I now know I am stuck pulling 8,000 lb fifth wheel, so my options to upgrade fifth trailer is very limited due to my truck.