Dodge will be adding particulate filters and oxides of nitrogen absorbers to their heavy duty diesel Rams starting in January of next year. Stricter emission standards will go into effect then which coincide with the rollout of low sulfur diesel fuel across the U.S. The filters will lower performance somewhat because of greater restriction in the exhaust so Dodge, like GM and Ford, plans other changes to make up for it.
The filters cannot tolerate high sulfur diesel so Dodge is waiting until January to add them to the production line because by then, all high sulfur diesel should be out of the pipelines.