A New York Times article (April 4, 2011) describes a radical engine design by Navistar to decrease nitrous oxide emissions and comply with the new EPA guidelines. This redesign and consequent launch delays hurt Navistar’s market share. But competitors used a “band aid” solution, using an add-on system with a fluid cocktail that neutralizes the nitrous oxide from the exhaust.  The article cites an effort by Navistar to demand that competitors too generate new compliant designs that take the nitrous oxide out completely rather than just manage the emissions.  Such design arguments have been left to the market by the EPA – with no preference for the nature of the solution developed as long as the companies are compliant. The add-on solution leaves the driver responsible to keep the chemicals filled, with alarms as a reminder. If the chemicals are not filled, the engine will not be compliant. Should Federal regulators recommend design choices for environmental compliance ? Should design compliance during use be “guaranteed” by the manufacturer or should it be the responsibility of the user of the product or the OEM who uses the engine ?