A tractor is a mostly large vehicle used to plow fields or as a form of transport moving items on a cart hooked on to the back for hay or other things farmers need to move from place to place.
well.. roughly if it is a non-refer unit. just a dry van they are 20,000 pounds. thats how you get the formula-20k truck 20k trailor...and 40,000 load. the 80,000 pound weight limit!