CARB Floats Final Modifications To Truck NOx Rules, With EPA Plan In Flux

Nine months after approving their landmark heavy-duty truck low-nitrogen oxide (NOx) regulation, California air board officials are proposing a lengthy set of testing, crediting and other regulatory modifications to the measure -- which takes effect with model year 2024 engines -- though they don’t change the core emissions standards. The modifications -- which trigger a new 30-day comment period for stakeholders but require only approval by the board’s executive officer and not the board members themselves -- once approved will...