Many many Mexican trucking companies are running NEW AMERICAN MADE Class 8 trucks
I would question this assertion. Are you certain about this? Many trucks are built in Mexico - Freightliner has two huge assembly plants - Intenational has long had a plant - as has Kenworth in Mexicali. All these trucks are American companies but the trucks are built in Mexico with many built for the Mexican market - though many are shipped to the US as well. The whole ULSD thing just has to do with various bolt on pieces of equipment used on US vehicles - they can either bolt them on or not.