I don't expect much relaxaction in an epa emissions changes under new adminstration. Why?? well, CA can set their own stds that must be met and EPA can't over rule them. And there are now multiple states that require CA emission stds. That is the majority or close to majority of all vehicles sold in the U.S. the states that require CA emissions are CA, Connecticut, Maine, Maryland, Massachusetts, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Vermont, and Washington.
So don't expect mfg to change much. as long as the must meet CA emissions for vehicles in these states they will do it or close for almost all vehicles. As an example, my 2015 duramax was delivered originally to an Idaho dealer, which doesn't require CA stds. But guess what it did and that's where my local dealer got the truck from and since oregon requires CA stds, no problem.
