WASHINGTON – The US Commerce Department said on Wednesday it is opening a probe into national security impacts of imports of medium-duty and heavy-duty trucks and related parts into the United States. The “Section 232” investigation could form the basis of grounds to impose new tariffs on work trucks, buses, vans and other larger vehicles. Tariffs would hurt Mexico, as it is the largest exporter of trucks to the US. …Canada and Japan are also large exporters of larger trucks to the US. The Commerce Department is seeking public comment by mid-May on the extent to which domestic production of trucks and truck parts can meet domestic demand. …It also wants comments on the impacts on prices “due to foreign unfair trade practices and state-sponsored overproduction”. …Higher tariffs on commercial vehicles could put pressure on transportation costs.