75 Pa.C.S. § 4942: Registered gross weight.

(a) Single vehicle limits.--No vehicle registered as a truck, a combination or a trailer shall be operated with a gross weight in excess of its registered gross weight.

(b) Truck towing trailer.--No vehicle registered as a truck shall be operated with a gross weight, exclusive of any trailer being towed, in excess of its registered gross weight as a truck.

(c) Combination.--No combination containing a trailer having a gross weight or registered gross weight in excess of 10,000 pounds shall be operated with a gross weight in excess of the registered gross weight of the truck or truck tractor for a combination. This subsection shall not apply to a combination of vehicles consisting of a motor vehicle towing a recreational trailer or recreational cargo trailer, registered as such, as long as the combination weight does not exceed the sum of the manufacturer's rated axle capacities or the gross combination weight rating, whichever is less.