There is a manufacture max gross combination(towing) weight.My Dodge 3500 is gvw at 12,200lbs my max combination weight is rated at 23,000lbs.I can only licence my total combo weight at the 23,000lbs even though my trailer is rated at 16,000lbs.Last night I was weighed at 20,200lbs,my fine was based on the difference of my truck gross and combo gross weight,8000lbs.