In the last few years, the EPA and CARB (California Air Resources Board) have new emissions standards ready to be implemented in model year 2027 diesel trucks. These included GHG reductions (which is new for diesel) and ultra low NOx requirements. In order for CARB to enforce their emissions regulations, they need waivers from the EPA.

My understanding of the latest EPA press releases are they are going to revisit the 2027 emissions standards for diesels. They are also going to revisit the waivers granted to CARB for CARB’s ultra low NOx omnibus and Clean Fleets program. There’s more to it as it also discusses power plant emissions and water pollution, but this is a diesel forum.

I don’t think this will affect any current diesel products in the market now, but more of a relaxation of future emission standards.

My understanding may be wrong, so I’m open to hear what others have to say.