Truck Engine Makers Wary of Looming California, EPA Pollution Plans (Corrected)

The Trump administration and California are crafting their own plans for addressing air pollution from diesel engines, and the nation’s engine makers and trucking industry fear they could be caught in a costly state-versus-federal vise by this time next year.

California wants to slash the federal standard for emissions of nitrogen oxide—a key cause of asthma and heart disease—by 90 percent from the limit that’s governed truck engines for nearly two decades. But the Environmental Protection Agency is working on its own target that may not be as stringent, although it has yet to release specific details.

Any updated standards ...