How much do I offer for a brand new 2017 Ram 2500 Diesel?

"You are correct the heavy diesel engine does take away almost 1000 lbs off the payload numbers."

Take all those numbers with a grain of salt. Where is the engine??? How much weight actually goes there when loaded???

Simply look at actual axle weights and then look at actual axle weight ratings.

Many times you will be over the GVWR but as long as you are not over axle ratings simply add tonnage.